Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:P11021 (
BiP
)
2,049
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The target of rapamycin (TOR) kinase integrates nutritional and stress signals to coordinately control cell growth in all eukaryotes. TOR associates with highly conserved proteins to constitute two distinct signaling complexes termed TORC1 and
TORC2
. Inactivation of TORC1 by rapamycin negatively regulates protein synthesis in most eukaryotes. Here, we report that down-regulation of TOR signaling by rapamycin in the model green alga Chlamydomonas reinhardtii resulted in pronounced phosphorylation of the endoplasmic reticulum chaperone
BiP
. Our results indicated that Chlamydomonas TOR regulates
BiP
phosphorylation through the control of protein synthesis, since rapamycin and cycloheximide have similar effects on
BiP
modification and protein synthesis inhibition. Modification of
BiP
by phosphorylation was suppressed under conditions that require the chaperone activity of
BiP
, such as heat shock stress or tunicamycin treatment, which inhibits N-linked glycosylation of nascent proteins in the endoplasmic reticulum. A phosphopeptide localized in the substrate-binding domain of
BiP
was identified in Chlamydomonas cells treated with rapamycin. This peptide contains a highly conserved threonine residue that might regulate
BiP
function, as demonstrated by yeast functional assays. Thus, our study has revealed a regulatory mechanism of
BiP
in Chlamydomonas by phosphorylation/dephosphorylation events and assigns a role to the TOR pathway in the control of
BiP
modification.
...
PMID:Inhibition of protein synthesis by TOR inactivation revealed a conserved regulatory mechanism of the BiP chaperone in Chlamydomonas. 2182 7
