ppwt 4

Question 1

what are the best known recruited tyrosine kinase activity

Answer 1

growth hormone,s prolactin, interferon and leptin

Question 2

how does it work the receptor with recruits tyrosine kinase activity

Answer 2

Growth hormone has 2 binding sites and binds to 2 receptor molecules. Dimerization of the cytoplasmic regions initiates signal transduction.

Question 3

what is the first step of receptors with recruites tyrosine kinase activity

Answer 3

JAK-2

Question 4

what is the JAK-STAT pathway

Answer 4

1. biding of interferons cross-links adjacent receptors and jacks cross phosphorylate each other on tyrosines
2. activated jacks phosphorylate receptors on tyrosine
3. after stats dock on specific phosphotyrosines on teh receptor, the Jacks phosphorylate them
4. stats dissociate from receptor and dimerize via their SH2 domain
5. stats migrate to nucleus, bind to DNA and other gene regulatory proteins and control gene expression

Question 5

explain the serine threonine kinase receptor

Answer 5

1. the ligand will bind to the TGF beta2
2. they will ecruit TGF BETA 1
3. upon binding smads are phosphorylated
4. a co smad will bind t the smads complex and they will go to the nucleus and regulate gene expression

Question 6

How is the response for intracellular receptor

Answer 6

they are slow since transcription and translation of protein is necessary

Question 7

What are some similar structures that all nuclear receptor domains have

Answer 7

1. DNA binding
2. P-box (where it detects a specific part of the amino acid sequence)
3. nuclear localization: amino acid sequence that is necessary for proteins that get into the nucleus
4. ligand binding domain: specific ligand that they bind to

Question 8

the nuclear receptor signalling mechanism pathway

Answer 8

1. prohormone enter they cytoplasm where it is metabolized into hormone or hormone enter
2. the hormone bind to a nuclear receptor
3. DNA sequence that is recognized is transcribed and then made into protein

Question 9

nuclear receptor regulation of gene expression
- repression
- activation

Answer 9

repression : multiple proteins (co repressors) that destabilize histone by removing acetylation - repressed gene expression

activation: hormone binding changes the combination of protein that acetylated histone and brings transcription and co-activators.

Question 10

true or false
many signaling pathways overlap resulting in a complex signaling network

Answer 10

true