Single Pass Receptor Signaling Flashcards
3 types of single pass receptors?
- cytokine receptors
- receptor Tyr kinasess (RTKs)
- TGF-beta receptors
Which receptors us an intrinsic kinase?
- RTKs
- TGFBRs
Which receptors us an extrinsic kinase?
- cytokine receptors
Describe JAK portion of JAK/STAT pathway (4)
- extrinsic kinase of cytokine R’s is JAK
- monomers dimerize after ligation
- activates JAK by autotransphosph. on Tyr res of JAK Lip domain
- JAK phosph’s Tyr on intracell domain of receptor
Scaffolding proteins are…? (3)
- SH2
- SH3
- PTB
Describe STAT portion of JAK/STAT pathway? (4)
- phosphoTyr serve as SH2 docking sites for STAT transc factors
- JAK phospho’s STAT
- STAT dimerizes
- STAT dimers –> nucleus –> gene expression
3 examples of JAK/STAT pathway?
- interferons
- lactation
- erythropoiesis (differentiation of hematopoietic cells)
Mechanism in erythropoiesis pathway? (3)
- erythropoietin (Epo) produced in kidneys
- stim’s RBC production in bone marrow
- Epo binds to Epo receptor (cytokine R) –> erythroid progenitor cells –> mature RBCs
Viruses implicated in MS? (2)
- Epstein-Barr virus
2. Herpes virus-6
Tx for MS? (2)
- Steroids reduce inflammation
2. Interferons signal JAK/STAT pathway –> anti-inflammatory signals + inhibit pro-inflammatory signals
Effect of mutating Gly-12 in Ras?
Blocks GAP binding –> perpetual GTP-bound state
2 examples of RTK pathways?
- growth factors
2. metabolism (insulin receptor)
Role of Human EGF Receptor (HER) pathway in cancer?
- HER2 amplification occurs in ~25% of breast cancers
- HER2 monoclonal antibodies are effective in tx for HER2 pos breast cancers
Pathway of TGFB/Smad signaling? (6)
- TGFB binds activated RII receptor
- RII recruits and phospho’s RI
- RI phospho’s Smad3
- 2 Smad3 + 1 Smad4 –> trimer complex thru phospho interactions
- complex imported into nucleus
- changes gene expression
Role of TGFB signaling in serum protease inhibition?
- Plasminogen activator inhibitor 1 (PAI1)
- prompts fibroblasts/epithelial cells –> stable tissue
