signal trans 3 part 3 Flashcards
clathrin polymerization accompanied by
vacuole formation in Enzyme-Linked Receptor term.
Release of — —-vesicle into cytoplasm
Shedding of ——- ———
Fusion of vesicle with ——– (internal —– ph)
Release of clathrin-coated vesicle into cytoplasm
Shedding of clathrin coat Fusion of vesicle with endosome (internal acidic ph
3rd step in Enzyme-Linked Receptor

tf in Enzyme-Linked Receptor: Termination
Potential recycling of receptors to plasma membrane is not possible
F
recycling happens at end
and
Transfer of remaining contents to lysosomes for degradation
tf Cytokine cant recruit manyintracellular signaling proteins
F it can recruit a broad range because of itts great diversity
tf the intracellular enzymatic activity has no intrincic enzymatic activity
t
single polypeptide
cytokine receptor
1st step of Cytokine Receptor action
Cytokine binding Dimerization
JAK activation and cross-phosphorylation Subunit phosphorylation

Cytokine receptor
multimeric complexes
STAT binding
prompts Phos Jak to phosphorylate it
2 thing phos in cytokine receptor activation
JAKS and subunits
upon sTAT phosphorylation
STAT dimerize
AND
Translocation to nucleus Altered gene expression
Protein phosphatases remove —- phosphates from the receptor and/or activated —–
Protein phosphatases remove tyrosine phosphates from the receptor and/or activated STATs.
Cytokine receptor termination
SOCS (suppressor of cytokine signaling)
inhibit STAT phosphorylation by binding
inhibiting JAKs or competing with STATs for phosphotyrosine binding sites
Multimeric formation of the receptor after ligand binding triggers —– of the ligand-receptor complex.
Multimeric formation of the receptor after ligand binding triggers endocytosis of the ligand-receptor complex.
cytokine receptor termination
importin α5
subunit of importin α5-β complex
Ran-GTP
dissociates
STAT1 dimer (NLS) and importin α5 complex
(happens in nucleus)
after dissociation of STAT 1 and importin a5
the STAT1 dimer
binds to DNA targets
and causes Expression of antiviral response
VP24 protein from EBola
Competes with STAT1 dimer for binding site on importin α5 subunit
VB24 and importin α5 subunit complex
diffuse thru nuclear pore
and Dissociated by complex by Ran-GTP
Suppression of antiviral response
promoted by VP24 protein after Dissociation from complex by Ran-GTP
Small KD
Receptor has high affinity for ligand.
Kd=
koff/ kon
Free = KD,
then Bound = 0.5 Bmax






