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Unformatted text preview: th inside
and outside of
many sgnals Largest family of cell surface receptors.
Mediate responses to an
enormous diversity of
including: hormones, local
G-protein linked receptors
in general consist of a
single polypeptide chain
that passes 7 times
through the lipid bilayer.
not flat in membrane, budle together like
this, crystal structure of rhodopsin with
retinal insisede it G proteins disassemble into two signaling
hetreotrimeric g proteins; got three
units when activatedcomponents, and hetero means three different components forming
a complex; gtpas but not g protein Inactive state: Both receptor and G
protein are inactive and not bound
the trimer; alpha is a gtpase. normally whe no sgnal, the alpha, beta and gamme bound
together with alpha boud to gdp; when signal compes and interactw with membrane
recpeto, translocates, the trimer interactw tith receptor, makes it change comformation,
akpha subunit releases gdp and attaches to gtp, making it active, beta and gamma remain
bound but detach from rest, alpha and TP stay bound but deslocate from the receptor Activation of receptor: G protein
associates with the receptor the trimer does not have a transmembrane domain but is
associated with membrane, how?linked to lipids alpha and
gamma protein linked to lipid Activated G protein: Binding to the
activated receptor enables the a
subunit of the G protein to
exchange its G...
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This note was uploaded on 02/23/2014 for the course MCDB 165A taught by Professor Iruela-arispe during the Winter '08 term at UCLA.
- Winter '08
- Cell Signaling