T cell receptor activation 2

Question 1

What type of proteins of the 435 proteins drugs target are the most common?

Answer 1

signal transduction proteins

Question 2

What region of the TCR contain the complementarity determining region?

Answer 2

the variable region—it interacts with antigen/MHC

Question 3

CDR1 and CDR2 are encoded by what region of the TCR>

Answer 3

the V region

Question 4

CDR3 is encoded by what region of the TCR?

Answer 4

The junction of V, D, and J

Question 5

What does CDR1, CDR 2, and CDR3 specifically bind?

Answer 5

1=mostly MHC but partially antigen
2= almost entirely the MHC
3= almost completely the Antigen

Question 6

What can DR3 do whether it is bound to or unbound ?

Answer 6

Change conformation

Question 7

T-F, The antigen/MHC complex only binds to the TCR and not to CD4/CD8?

Answer 7

False—It binds to both

Question 8

Does the TCR and CD4/CD8 that are bound to the same antigen/MHC complex associate with each other?

Answer 8

No

Question 9

Which CD co receptor is a monomer? a heterodimer?

Answer 9

monomer= CD4
heterodimer= CD8

Question 10

Where do the CD4 and CD8 molecules bind on MHC?

Answer 10

invariant regions distant from the cleft—they greatly enhance the sensitivity

Question 11

Why is CD4/CD8 enhancement necessary?

Answer 11

low number of MHC/antigen complexes on the cell that a single TCR can interact with needsenhancement

Question 12

Do TCR{ form homo or heterodimers?

Answer 12

homodimers

Question 13

does CD3 epsilon form homo or heterodimers?

Answer 13

heterodimer with gamma on one side and with delta on the otehr

Question 14

What do the CD3 subunits and the TCR{ subunits contain?

Answer 14

ITAM-immuno tyrosine based activation motifs yxxlx6-8yxxl

Question 15

What initiates intracellular signaling from the TCR?

Answer 15

phosphorylation of ITAMS by tyrosine kinase LcK—-> recruit and bind zap-70

Question 16

Zap-70 phosphorylates what?

Answer 16

LAT- form binding site for multiple signaling proteins

Question 17

What does PLC-gamma form by cleaving phosphatidyl inositol?

Answer 17

diacylglycerol for PKC or inositol 1,4,5 phosphate for Ca influx
(DAG and IP3)

Question 18

What does SLP-76 bind and what does it recruit?

Answer 18

LAT and recruits ITK

Question 19

What does PLC-gamma bind and what activates it?

Answer 19

LAT and phosphorylated by ITK

Question 20

What does PI3kinase do?

Answer 20

phosphorylates phosphatidyl inositol to form PIP3.

Question 21

What very important downstream regulator of activity, cell survival, apoptosis, translation, TF activation and metabolism is activated by PI3 kinase?

Answer 21

Akt

Question 22

What does recruitment of GEF to LAT do?

Answer 22

stimulation of G proteins—>kinase cascades

ras>raf>mek>erk>TFs

Question 23

What pathway does calcium inflow cause?

Answer 23

Ca>binds calmodulin> binds calcineurin> dephosphorylates NFAT a TF»nuclease to drive transcription

Question 24

What is critical for the activation of the NF-kB pathway

Answer 24

protein degradation

Question 25

Pathway of NF-kB activation?

Answer 25

DAG>IKK complex> phosphorylate I-kB> I-kB is degraded> releases NF-kB

Question 26

What does partial degradation of p100 lead to?

Answer 26

formation of p52

Question 27

Where do TFs bind to regulate genes?

Answer 27

promoter region

Question 28

What drives morphological changes in Tcell function?

Answer 28

actin polymerization and rearrangement—occur within minutes after activation

Question 29

What is Vav1?

Answer 29

GEF recruited by LAT

Question 30

What does Vav1 do?

Answer 30

Activates Rac, CDC42 and NCK.

Question 31

NcK binds to what>

Answer 31

WASp

Question 32

What does Rac/CDC42 and WASp lead to?

Answer 32

Arp2/3–>actin branching (mutations in any of these causes sever Tcell defects)