mcb test 3: enzyme coupled receptors

RTKs

receptor tyrosine kinases

what do RTKs do?

bind a ligand so tyrosine kinases can phosphorylate and produce various functions

what kind of receptor is an RTK?

a single pass transmembrane receptor

how many different kinds of mechanisms do RTKs use?

all use the same mechanism

canonical RTK pathway

activated RTK -> 2 receptors dimerize -> transphosphorylation and RTK is fully active -> autophosphorylation of receptors at tyrosines -> P-RTKs act as a scaffold for d/s signal proteins

unique ligands bind

unique receptors

EGF

epithelial growth factor

eye facets in drosophila are called

ommatidia

EGFR

aka Sevenless- no 7th facet

typical in drosophila

EGF canonical pathway

EGF -> Sevenless (EGFR) phosphorylates -> Grb2 -> SoS (RasGEF) -> RAsGEF binds GTP -> MAP kinase cascade (Raf->Mek->Erk) -> P-Erk: cytosolic protein changes OR PP-Erk: gene expression in nucleus changes

Eph pathway

contact dependent pathway wherein dimerized ligand-receptor complexes crossphosphorylate

Eph pathway ligands

ephesians