Cell Communication презентация

Содержание

1. Cell Communication
2. Overview: The Cellular Internet Cell-to-cell communication is
3. Fig. 11-1
4. Concept 11.1: External signals are converted to
5. Evolution of Cell Signaling A signal transduction
6. Fig. 11-2 Receptor α
7. Pathway similarities suggest that ancestral signaling molecules
8. Fig. 11-3 Individual rod-
9. Local and Long-Distance Signaling Cells in a
10. Fig. 11-4 Plasma membranes Gap junctions between
11. In many other cases, animal cells communicate
12. Fig. 11-5 Local signaling Target cell Secreting
13. Fig. 11-5ab Local signaling Target cell
14. Fig. 11-5c Long-distance signaling Endocrine cell Blood
15. The Three Stages of Cell Signaling: A
16. Fig. 11-6-1 Reception 1 EXTRACELLULAR FLUID Signaling molecule Plasma membrane CYTOPLASM 1 Receptor
17. Fig. 11-6-2 1 EXTRACELLULAR FLUID Signaling molecule
18. Fig. 11-6-3 EXTRACELLULAR FLUID Plasma
19. Concept 11.2: Reception: A signal molecule binds
20. Receptors in the Plasma Membrane Most water-soluble
21. A G protein-coupled receptor is a plasma
22. Fig. 11-7a Signaling-molecule binding site Segment that interacts with G proteins G protein-coupled receptor
23. Fig. 11-7b G
24. Receptor tyrosine kinases are membrane receptors that
25. Fig. 11-7c Signaling
26. A ligand-gated ion channel receptor acts as
27. Fig. 11-7d Signaling molecule
28. Intracellular Receptors Some receptor proteins are intracellular,
29. Fig. 11-8-1 Hormone (testosterone) Receptor protein Plasma membrane EXTRACELLULAR FLUID DNA NUCLEUS CYTOPLASM
30. Fig. 11-8-2 Receptor protein Hormone (testosterone) EXTRACELLULAR
31. Fig. 11-8-3 Hormone (testosterone) EXTRACELLULAR FLUID Receptor
32. Fig. 11-8-4 Hormone (testosterone) EXTRACELLULAR FLUID Plasma
33. Fig. 11-8-5 Hormone (testosterone) EXTRACELLULAR FLUID Receptor
34. Concept 11.3: Transduction: Cascades of molecular interactions
35. Signal Transduction Pathways The molecules that relay
36. Protein Phosphorylation and Dephosphorylation In many pathways,
37. Protein phosphatases remove the phosphates from proteins,
38. Fig. 11-9 Signaling molecule Receptor Activated relay
39. Small Molecules and Ions as Second Messengers
40. Cyclic AMP Cyclic AMP (cAMP) is one
41. Adenylyl cyclase Fig. 11-10 Pyrophosphate P P i ATP cAMP Phosphodiesterase AMP
42. Many signal molecules trigger formation of cAMP
43. First messenger Fig. 11-11 G protein Adenylyl
44. Calcium Ions and Inositol Triphosphate (IP3) Calcium
45. EXTRACELLULAR FLUID Fig. 11-12 ATP Nucleus Mitochondrion
46. A signal relayed by a signal transduction
47. Fig. 11-13-1 EXTRA- CELLULAR FLUID Signaling molecule
48. Fig. 11-13-2 G protein EXTRA- CELLULAR FLUID
49. Fig. 11-13-3 G protein EXTRA- CELLULAR FLUID
50. Concept 11.4: Response: Cell signaling leads to
51. Nuclear and Cytoplasmic Responses Ultimately, a signal
52. Fig. 11-14 Growth factor
53. Other pathways regulate the activity of enzymes
54. Fig. 11-15 Reception Transduction
55. Signaling pathways can also affect the physical
57. Fig. 11-16a RESULTS Wild-type (shmoos) ∆Fus3 ∆formin
58. Fig. 11-16b
59. Fine-Tuning of the Response Multistep pathways have
60. Signal Amplification Enzyme cascades amplify the cell’s
61. The Specificity of Cell Signaling and Coordination
62. Fig. 11-17 Signaling molecule Receptor Relay molecules
63. Fig. 11-17a Signaling molecule Receptor Relay molecules
64. Fig. 11-17b Response 4 Response 5 Activation
65. Signaling Efficiency: Scaffolding Proteins and Signaling Complexes
66. Fig. 11-18 Signaling molecule Receptor Scaffolding protein Plasma membrane Three different protein kinases
67. Termination of the Signal Inactivation mechanisms are
68. Concept 11.5: Apoptosis (programmed cell death) integrates
69. Fig. 11-19 2 µm
70. Apoptosis in the Soil Worm Caenorhabditis elegans
71. Fig. 11-20 Ced-9 protein (active) inhibits Ced-4
72. Fig. 11-20a Ced-9 protein (active) inhibits Ced-4
73. Fig. 11-20b (b) Death signal Death- signaling
74. Apoptotic Pathways and the Signals That Trigger
75. Apoptosis evolved early in animal evolution and
76. Fig. 11-21 Interdigital tissue 1 mm
77. Fig. 11-UN1 Reception Transduction
78. Fig. 11-UN2
79. You should now be able to: Describe
80. Define the term second messenger; briefly describe

Overview: The Cellular Internet Cell-to-cell communication is essential for multicellular organisms Biologists have discovered some universal mechanisms of cellular regulation The combined effects of multiple signals determine cell response For example,

Слайд 1Chapter 11
Cell Communication

Слайд 2Overview: The Cellular Internet
Cell-to-cell communication is essential for multicellular organisms
Biologists have

discovered some universal mechanisms of cellular regulation
The combined effects of multiple signals determine cell response
For example, the dilation of blood vessels is controlled by multiple molecules

Слайд 3Fig. 11-1

Слайд 4Concept 11.1: External signals are converted to responses within the cell
Microbes

are a window on the role of cell signaling in the evolution of life

Слайд 5Evolution of Cell Signaling
A signal transduction pathway is a series of

steps by which a signal on a cell’s surface is converted into a specific cellular response
Signal transduction pathways convert signals on a cell’s surface into cellular responses

Слайд 6

Fig. 11-2
Receptor
α factor
a factor
a
α
α
a
Exchange
of mating
factors
Yeast cell,
mating type a
Yeast cell,
mating type α
Mating
New

a/α
cell

a/α

Слайд 7Pathway similarities suggest that ancestral signaling molecules evolved in prokaryotes and

were modified later in eukaryotes
The concentration of signaling molecules allows bacteria to detect population density

Слайд 8

Fig. 11-3
Individual rod-
shaped cells
Spore-forming
structure
(fruiting body)
Aggregation in
process
Fruiting bodies
0.5 mm
1
3
2

Слайд 9Local and Long-Distance Signaling
Cells in a multicellular organism communicate by chemical

messengers
Animal and plant cells have cell junctions that directly connect the cytoplasm of adjacent cells
In local signaling, animal cells may communicate by direct contact, or cell-cell recognition

Слайд 10Fig. 11-4
Plasma membranes
Gap junctions
between animal cells
(a) Cell junctions
Plasmodesmata
between plant cells
(b) Cell-cell

recognition

Слайд 11In many other cases, animal cells communicate using local regulators, messenger

molecules that travel only short distances
In long-distance signaling, plants and animals use chemicals called hormones

Слайд 12Fig. 11-5
Local signaling
Target cell
Secreting
cell
Secretory
vesicle
Local regulator
diffuses through
extracellular fluid
(a) Paracrine signaling
(b) Synaptic signaling
Target

cell
is stimulated

Neurotransmitter
diffuses across
synapse

Electrical signal
along nerve cell
triggers release of
neurotransmitter

Long-distance signaling

Endocrine cell

Blood
vessel

Hormone travels
in bloodstream
to target cells

Target
cell

Слайд 13Fig. 11-5ab
Local signaling

Target cell
Secretory
vesicle
Secreting
cell
Local regulator
diffuses through
extracellular fluid
(a) Paracrine signaling
(b) Synaptic signaling
Target

cell
is stimulated

Neurotransmitter
diffuses across
synapse

Electrical signal
along nerve cell
triggers release of
neurotransmitter

Слайд 14Fig. 11-5c
Long-distance signaling
Endocrine cell
Blood
vessel
Hormone travels
in bloodstream
to target cells
Target
cell
(c) Hormonal signaling

Слайд 15The Three Stages of Cell Signaling: A Preview
Earl W. Sutherland discovered

how the hormone epinephrine acts on cells
Sutherland suggested that cells receiving signals went through three processes:
Reception
Transduction
Response

Animation: Overview of Cell Signaling

Слайд 16Fig. 11-6-1
Reception
1
EXTRACELLULAR
FLUID
Signaling
molecule
Plasma membrane
CYTOPLASM

1
Receptor

Слайд 17Fig. 11-6-2
1
EXTRACELLULAR
FLUID
Signaling
molecule
Plasma membrane
CYTOPLASM

Transduction
2
Relay molecules in a signal transduction pathway
Reception

1
Receptor

Слайд 18

Fig. 11-6-3
EXTRACELLULAR
FLUID
Plasma membrane
CYTOPLASM
Receptor
Signaling
molecule
Relay molecules in a signal transduction pathway
Activation
of cellular
response
Transduction
Response
2
3
Reception

1

Слайд 19Concept 11.2: Reception: A signal molecule binds to a receptor protein,

causing it to change shape

The binding between a signal molecule (ligand) and receptor is highly specific
A shape change in a receptor is often the initial transduction of the signal
Most signal receptors are plasma membrane proteins

Слайд 20Receptors in the Plasma Membrane
Most water-soluble signal molecules bind to specific

sites on receptor proteins in the plasma membrane
There are three main types of membrane receptors:
G protein-coupled receptors
Receptor tyrosine kinases
Ion channel receptors

Слайд 21A G protein-coupled receptor is a plasma membrane receptor that works

with the help of a G protein
The G protein acts as an on/off switch: If GDP is bound to the G protein, the G protein is inactive

Слайд 22Fig. 11-7a
Signaling-molecule binding site
Segment that
interacts with
G proteins
G protein-coupled receptor

Слайд 23

Fig. 11-7b
G protein-coupled
receptor
Plasma
membrane
Enzyme
G protein
(inactive)
GDP
CYTOPLASM
Activated
enzyme
GTP
Cellular response
GDP
P
i
Activated
receptor
GDP
GTP
Signaling molecule
Inactive
enzyme
1
2
3
4

Слайд 24Receptor tyrosine kinases are membrane receptors that attach phosphates to tyrosines
A

receptor tyrosine kinase can trigger multiple signal transduction pathways at once

Слайд 25

Fig. 11-7c
Signaling
molecule (ligand)
Ligand-binding site
α Helix
Tyrosines
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Receptor tyrosine
kinase proteins
CYTOPLASM
Signaling
molecule
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
Dimer
Activated relay
proteins
Tyr
Tyr
Tyr
Tyr
Tyr
Tyr
P
P
P
P
P
P
Cellular
response 1
Cellular
response 2
Inactive
relay proteins
Activated

tyrosine
kinase regions

Fully activated receptor
tyrosine kinase

6 ADP

ATP

Tyr

Слайд 26A ligand-gated ion channel receptor acts as a gate when the

receptor changes shape
When a signal molecule binds as a ligand to the receptor, the gate allows specific ions, such as Na+ or Ca2+, through a channel in the receptor

Слайд 27

Fig. 11-7d
Signaling
molecule
(ligand)
Gate
closed
Ions
Ligand-gated
ion channel receptor
Plasma
membrane
Gate open
Cellular
response
Gate closed
3
2
1

Слайд 28Intracellular Receptors
Some receptor proteins are intracellular, found in the cytosol or

nucleus of target cells
Small or hydrophobic chemical messengers can readily cross the membrane and activate receptors
Examples of hydrophobic messengers are the steroid and thyroid hormones of animals
An activated hormone-receptor complex can act as a transcription factor, turning on specific genes

Слайд 29Fig. 11-8-1
Hormone
(testosterone)
Receptor
protein
Plasma
membrane
EXTRACELLULAR
FLUID
DNA
NUCLEUS
CYTOPLASM

Слайд 30Fig. 11-8-2
Receptor
protein
Hormone
(testosterone)
EXTRACELLULAR
FLUID
Plasma
membrane
Hormone-
receptor
complex
DNA
NUCLEUS
CYTOPLASM

Слайд 31Fig. 11-8-3
Hormone
(testosterone)
EXTRACELLULAR
FLUID
Receptor
protein
Plasma
membrane
Hormone-
receptor
complex
DNA
NUCLEUS
CYTOPLASM

Слайд 32Fig. 11-8-4
Hormone
(testosterone)
EXTRACELLULAR
FLUID
Plasma
membrane
Receptor
protein
Hormone-
receptor
complex
DNA
mRNA
NUCLEUS
CYTOPLASM

Слайд 33Fig. 11-8-5
Hormone
(testosterone)
EXTRACELLULAR
FLUID
Receptor
protein
Plasma
membrane
Hormone-
receptor
complex
DNA
mRNA
NUCLEUS
New protein
CYTOPLASM

Слайд 34Concept 11.3: Transduction: Cascades of molecular interactions relay signals from receptors

to target molecules in the cell

Signal transduction usually involves multiple steps
Multistep pathways can amplify a signal: A few molecules can produce a large cellular response
Multistep pathways provide more opportunities for coordination and regulation of the cellular response

Слайд 35Signal Transduction Pathways
The molecules that relay a signal from receptor to

response are mostly proteins
Like falling dominoes, the receptor activates another protein, which activates another, and so on, until the protein producing the response is activated
At each step, the signal is transduced into a different form, usually a shape change in a protein

Слайд 36Protein Phosphorylation and Dephosphorylation
In many pathways, the signal is transmitted by

a cascade of protein phosphorylations
Protein kinases transfer phosphates from ATP to protein, a process called phosphorylation

Слайд 37Protein phosphatases remove the phosphates from proteins, a process called dephosphorylation
This

phosphorylation and dephosphorylation system acts as a molecular switch, turning activities on and off

Слайд 38Fig. 11-9
Signaling molecule
Receptor
Activated relay
molecule
Inactive
protein kinase
1
Active
protein
kinase
1
Inactive
protein kinase
2
ATP
ADP
Active
protein
kinase
2
P
P
PP
Inactive
protein kinase
3
ATP
ADP
Active
protein
kinase
3
P
P
PP
i
ATP
ADP
P
Active
protein
PP
P
i
Inactive
protein
Cellular
response
Phosphorylation cascade

i

Слайд 39Small Molecules and Ions as Second Messengers
The extracellular signal molecule that

binds to the receptor is a pathway’s “first messenger”
Second messengers are small, nonprotein, water-soluble molecules or ions that spread throughout a cell by diffusion
Second messengers participate in pathways initiated by G protein-coupled receptors and receptor tyrosine kinases
Cyclic AMP and calcium ions are common second messengers

Слайд 40Cyclic AMP
Cyclic AMP (cAMP) is one of the most widely used

second messengers
Adenylyl cyclase, an enzyme in the plasma membrane, converts ATP to cAMP in response to an extracellular signal

Слайд 41Adenylyl cyclase
Fig. 11-10
Pyrophosphate
P
P
i
ATP
cAMP
Phosphodiesterase
AMP

Слайд 42Many signal molecules trigger formation of cAMP
Other components of cAMP pathways

are G proteins, G protein-coupled receptors, and protein kinases
cAMP usually activates protein kinase A, which phosphorylates various other proteins
Further regulation of cell metabolism is provided by G-protein systems that inhibit adenylyl cyclase

Слайд 43First messenger
Fig. 11-11
G protein
Adenylyl
cyclase
GTP
ATP
cAMP
Second
messenger
Protein
kinase A
G protein-coupled
receptor
Cellular responses

Слайд 44Calcium Ions and Inositol Triphosphate (IP3)
Calcium ions (Ca2+) act as a

second messenger in many pathways
Calcium is an important second messenger because cells can regulate its concentration

Слайд 45EXTRACELLULAR
FLUID
Fig. 11-12
ATP
Nucleus
Mitochondrion
Ca2+ pump
Plasma
membrane
CYTOSOL
Ca2+
pump
Endoplasmic
reticulum (ER)
Ca2+
pump
ATP
Key
High [Ca2+]
Low [Ca2+]

Слайд 46A signal relayed by a signal transduction pathway may trigger an

increase in calcium in the cytosol
Pathways leading to the release of calcium involve inositol triphosphate (IP3) and diacylglycerol (DAG) as additional second messengers

Animation: Signal Transduction Pathways

Слайд 47Fig. 11-13-1
EXTRA-
CELLULAR
FLUID
Signaling molecule
(first messenger)
G protein
GTP
G protein-coupled
receptor
Phospholipase C
PIP2
IP3
DAG
(second messenger)
IP3-gated
calcium channel
Endoplasmic
reticulum (ER)
Ca2+
CYTOSOL

Слайд 48Fig. 11-13-2
G protein
EXTRA-
CELLULAR
FLUID
Signaling molecule
(first messenger)
G protein-coupled
receptor
Phospholipase C
PIP2
DAG
IP3
(second messenger)
IP3-gated
calcium channel
Endoplasmic
reticulum (ER)
Ca2+
CYTOSOL
Ca2+
(second
messenger)
GTP

Слайд 49Fig. 11-13-3
G protein
EXTRA-
CELLULAR
FLUID
Signaling molecule
(first messenger)
G protein-coupled
receptor
Phospholipase C
PIP2
DAG
IP3
(second messenger)
IP3-gated
calcium channel
Endoplasmic
reticulum (ER)
Ca2+
CYTOSOL
Various
proteins
activated
Cellular
responses
Ca2+
(second
messenger)
GTP

Слайд 50Concept 11.4: Response: Cell signaling leads to regulation of transcription or

cytoplasmic activities

The cell’s response to an extracellular signal is sometimes called the “output response”

Слайд 51Nuclear and Cytoplasmic Responses
Ultimately, a signal transduction pathway leads to regulation

of one or more cellular activities
The response may occur in the cytoplasm or may involve action in the nucleus
Many signaling pathways regulate the synthesis of enzymes or other proteins, usually by turning genes on or off in the nucleus
The final activated molecule may function as a transcription factor

Слайд 52

Fig. 11-14
Growth factor
Receptor
Phosphorylation
cascade
Reception
Transduction
Active
transcription
factor
Response
P
Inactive
transcription
factor
CYTOPLASM
DNA
NUCLEUS
mRNA
Gene

Слайд 53Other pathways regulate the activity of enzymes

Copyright © 2008 Pearson Education,

Inc., publishing as Pearson Benjamin Cummings

Слайд 54

Fig. 11-15
Reception
Transduction
Response
Binding of epinephrine to G protein-coupled receptor (1 molecule)
Inactive G

protein

Active G protein (102 molecules)

Inactive adenylyl cyclase

Active adenylyl cyclase (102)

ATP

Cyclic AMP (104)

Inactive protein kinase A

Active protein kinase A (104)

Inactive phosphorylase kinase

Active phosphorylase kinase (105)

Inactive glycogen phosphorylase

Active glycogen phosphorylase (106)

Glycogen

Glucose-1-phosphate
(108 molecules)

Слайд 55Signaling pathways can also affect the physical characteristics of a cell,

for example, cell shape

Слайд 56

Fig. 11-16
RESULTS
CONCLUSION
Wild-type (shmoos)
∆Fus3
∆formin
Shmoo projection forming
Formin
P
Actin
subunit
P
P
Formin
Formin
Fus3
Phosphory-
lation
cascade
GTP
G

protein-coupled
receptor

Mating
factor

GDP

Fus3

Microfilament

Слайд 57
Fig. 11-16a
RESULTS
Wild-type (shmoos)
∆Fus3
∆formin

Слайд 58

Fig. 11-16b
CONCLUSION
Mating
factor
G protein-coupled
receptor
GDP
GTP
Phosphory-
lation
cascade
Shmoo projection
forming
Fus3
Fus3
Fus3
Formin
Formin
P
P
P
Formin
P
Actin
subunit
Microfilament
1
2
3
4

5

Слайд 59Fine-Tuning of the Response
Multistep pathways have two important benefits:
Amplifying the signal

(and thus the response)
Contributing to the specificity of the response

Слайд 60Signal Amplification
Enzyme cascades amplify the cell’s response
At each step, the number

of activated products is much greater than in the preceding step

Слайд 61The Specificity of Cell Signaling and Coordination of the Response
Different kinds

of cells have different collections of proteins
These different proteins allow cells to detect and respond to different signals
Even the same signal can have different effects in cells with different proteins and pathways
Pathway branching and “cross-talk” further help the cell coordinate incoming signals

Слайд 62Fig. 11-17
Signaling
molecule
Receptor
Relay
molecules
Response 1
Cell A. Pathway leads
to a single response.
Response 2
Response 3
Cell

B. Pathway branches,
leading to two responses.

Response 4

Response 5

Activation
or inhibition

Cell C. Cross-talk occurs
between two pathways.

Cell D. Different receptor
leads to a different response.

Слайд 63Fig. 11-17a
Signaling
molecule
Receptor
Relay
molecules
Response 1
Cell A. Pathway leads
to a single response.
Cell B. Pathway

branches,
leading to two responses.

Response 2

Response 3

Слайд 64Fig. 11-17b
Response 4
Response 5
Activation
or inhibition
Cell C. Cross-talk occurs
between two pathways.
Cell D.

Different receptor
leads to a different response.

Слайд 65Signaling Efficiency: Scaffolding Proteins and Signaling Complexes
Scaffolding proteins are large relay

proteins to which other relay proteins are attached
Scaffolding proteins can increase the signal transduction efficiency by grouping together different proteins involved in the same pathway

Слайд 66Fig. 11-18
Signaling
molecule
Receptor
Scaffolding
protein
Plasma
membrane
Three
different
protein
kinases

Слайд 67Termination of the Signal
Inactivation mechanisms are an essential aspect of cell

signaling
When signal molecules leave the receptor, the receptor reverts to its inactive state

Слайд 68Concept 11.5: Apoptosis (programmed cell death) integrates multiple cell-signaling pathways
Apoptosis is

programmed or controlled cell suicide
A cell is chopped and packaged into vesicles that are digested by scavenger cells
Apoptosis prevents enzymes from leaking out of a dying cell and damaging neighboring cells

Слайд 69Fig. 11-19
2 µm

Слайд 70Apoptosis in the Soil Worm Caenorhabditis elegans
Apoptosis is important in shaping

an organism during embryonic development
The role of apoptosis in embryonic development was first studied in Caenorhabditis elegans
In C. elegans, apoptosis results when specific proteins that “accelerate” apoptosis override those that “put the brakes” on apoptosis

Слайд 71Fig. 11-20
Ced-9
protein (active)
inhibits Ced-4
activity
Mitochondrion
Receptor
for death-
signaling
molecule
Ced-4
Ced-3
Inactive proteins

(a) No death signal
Ced-9
(inactive)
Cell
forms
blebs
Death-
signaling
molecule
Other
proteases
Active
Ced-4
Active
Ced-3
Nucleases
Activation
cascade
(b) Death signal

Слайд 72Fig. 11-20a
Ced-9
protein (active)
inhibits Ced-4
activity
Mitochondrion
Ced-4
Ced-3
Receptor
for death-
signaling
molecule

Inactive proteins
(a) No death signal

Слайд 73Fig. 11-20b
(b) Death signal
Death-
signaling
molecule
Ced-9
(inactive)
Cell
forms
blebs
Active
Ced-4
Active
Ced-3
Activation
cascade
Other
proteases
Nucleases

Слайд 74Apoptotic Pathways and the Signals That Trigger Them
Caspases are the main

proteases (enzymes that cut up proteins) that carry out apoptosis
Apoptosis can be triggered by:
An extracellular death-signaling ligand
DNA damage in the nucleus
Protein misfolding in the endoplasmic reticulum

Слайд 75Apoptosis evolved early in animal evolution and is essential for the

development and maintenance of all animals
Apoptosis may be involved in some diseases (for example, Parkinson’s and Alzheimer’s); interference with apoptosis may contribute to some cancers

Слайд 76Fig. 11-21
Interdigital tissue
1 mm

Слайд 77

Fig. 11-UN1
Reception
Transduction
Response
Receptor
Relay molecules
Signaling
molecule
Activation
of cellular
response
1
2
3

Слайд 78Fig. 11-UN2

Слайд 79You should now be able to:
Describe the nature of a ligand-receptor

interaction and state how such interactions initiate a signal-transduction system
Compare and contrast G protein-coupled receptors, tyrosine kinase receptors, and ligand-gated ion channels
List two advantages of a multistep pathway in the transduction stage of cell signaling
Explain how an original signal molecule can produce a cellular response when it may not even enter the target cell

Слайд 80Define the term second messenger; briefly describe the role of these

molecules in signaling pathways
Explain why different types of cells may respond differently to the same signal molecule
Describe the role of apoptosis in normal development and degenerative disease in vertebrates

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Cell Communication презентация

Содержание

Слайд 1Chapter 11Cell Communication

Слайд 2Overview: The Cellular InternetCell-to-cell communication is essential for multicellular organismsBiologists have

Слайд 3Fig. 11-1

Слайд 4Concept 11.1: External signals are converted to responses within the cellMicrobes

Слайд 5Evolution of Cell SignalingA signal transduction pathway is a series of

Слайд 6Fig. 11-2Receptorα factora factoraααaExchangeof matingfactorsYeast cell,mating type aYeast cell,mating type αMatingNew

Слайд 7Pathway similarities suggest that ancestral signaling molecules evolved in prokaryotes and

Слайд 8Fig. 11-3Individual rod-shaped cellsSpore-formingstructure(fruiting body)Aggregation inprocessFruiting bodies0.5 mm132

Слайд 9Local and Long-Distance SignalingCells in a multicellular organism communicate by chemical

Слайд 10Fig. 11-4Plasma membranesGap junctionsbetween animal cells(a) Cell junctionsPlasmodesmatabetween plant cells(b) Cell-cell

Слайд 11In many other cases, animal cells communicate using local regulators, messenger

Слайд 12Fig. 11-5Local signalingTarget cellSecretingcellSecretoryvesicleLocal regulatordiffuses throughextracellular fluid(a) Paracrine signaling(b) Synaptic signalingTarget

Слайд 13Fig. 11-5abLocal signalingTarget cellSecretoryvesicleSecretingcellLocal regulatordiffuses throughextracellular fluid(a) Paracrine signaling(b) Synaptic signalingTarget

Слайд 14Fig. 11-5cLong-distance signalingEndocrine cellBloodvesselHormone travelsin bloodstreamto target cellsTargetcell(c) Hormonal signaling

Слайд 15The Three Stages of Cell Signaling: A PreviewEarl W. Sutherland discovered

Слайд 16Fig. 11-6-1Reception1EXTRACELLULARFLUIDSignalingmoleculePlasma membraneCYTOPLASM1Receptor

Слайд 17Fig. 11-6-21EXTRACELLULARFLUIDSignalingmoleculePlasma membraneCYTOPLASMTransduction2Relay molecules in a signal transduction pathwayReception1Receptor

Слайд 18Fig. 11-6-3EXTRACELLULARFLUIDPlasma membraneCYTOPLASMReceptorSignalingmoleculeRelay molecules in a signal transduction pathwayActivationof cellularresponseTransductionResponse23Reception1

Слайд 19Concept 11.2: Reception: A signal molecule binds to a receptor protein,

Слайд 20Receptors in the Plasma MembraneMost water-soluble signal molecules bind to specific

Слайд 21A G protein-coupled receptor is a plasma membrane receptor that works

Слайд 22Fig. 11-7aSignaling-molecule binding siteSegment thatinteracts withG proteinsG protein-coupled receptor

Слайд 23Fig. 11-7bG protein-coupledreceptorPlasmamembraneEnzymeG protein(inactive)GDPCYTOPLASMActivatedenzymeGTPCellular responseGDPPiActivatedreceptorGDPGTPSignaling moleculeInactiveenzyme1234

Слайд 24Receptor tyrosine kinases are membrane receptors that attach phosphates to tyrosinesA

Слайд 26A ligand-gated ion channel receptor acts as a gate when the

Слайд 27Fig. 11-7dSignalingmolecule(ligand)GateclosedIonsLigand-gatedion channel receptorPlasmamembraneGate openCellularresponseGate closed321

Слайд 28Intracellular ReceptorsSome receptor proteins are intracellular, found in the cytosol or

Слайд 29Fig. 11-8-1Hormone(testosterone)ReceptorproteinPlasmamembraneEXTRACELLULARFLUIDDNANUCLEUSCYTOPLASM

Слайд 30Fig. 11-8-2ReceptorproteinHormone(testosterone)EXTRACELLULARFLUIDPlasmamembraneHormone-receptorcomplexDNANUCLEUSCYTOPLASM

Слайд 31Fig. 11-8-3Hormone(testosterone)EXTRACELLULARFLUIDReceptorproteinPlasmamembraneHormone-receptorcomplexDNANUCLEUSCYTOPLASM

Слайд 32Fig. 11-8-4Hormone(testosterone)EXTRACELLULARFLUIDPlasmamembraneReceptorproteinHormone-receptorcomplexDNAmRNANUCLEUSCYTOPLASM

Слайд 33Fig. 11-8-5Hormone(testosterone)EXTRACELLULARFLUIDReceptorproteinPlasmamembraneHormone-receptorcomplexDNAmRNANUCLEUSNew proteinCYTOPLASM

Слайд 34Concept 11.3: Transduction: Cascades of molecular interactions relay signals from receptors

Слайд 35Signal Transduction PathwaysThe molecules that relay a signal from receptor to

Слайд 36Protein Phosphorylation and DephosphorylationIn many pathways, the signal is transmitted by

Слайд 37Protein phosphatases remove the phosphates from proteins, a process called dephosphorylationThis

Слайд 39Small Molecules and Ions as Second MessengersThe extracellular signal molecule that

Слайд 40Cyclic AMPCyclic AMP (cAMP) is one of the most widely used

Слайд 41Adenylyl cyclaseFig. 11-10PyrophosphatePPiATPcAMPPhosphodiesteraseAMP

Слайд 42Many signal molecules trigger formation of cAMPOther components of cAMP pathways

Слайд 43First messengerFig. 11-11G proteinAdenylylcyclaseGTPATPcAMPSecondmessengerProteinkinase AG protein-coupledreceptorCellular responses

Слайд 44Calcium Ions and Inositol Triphosphate (IP3)Calcium ions (Ca2+) act as a

Слайд 45EXTRACELLULARFLUIDFig. 11-12ATPNucleusMitochondrionCa2+ pumpPlasmamembraneCYTOSOLCa2+pumpEndoplasmicreticulum (ER)Ca2+pumpATPKeyHigh [Ca2+]Low [Ca2+]