Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.25 (MEKK1)
 1,856 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hsp90 functions in association with several cochaperones for folding of protein kinases and transcription factors, although the relative contribution of each to the overall reaction is unknown. We assayed the role of nine different cochaperones in the activation of Ste11, a Saccharomyces cerevisiae mitogen-activated protein kinase kinase kinase. Studies on signaling via this protein kinase pathway was measured by alpha-factor-stimulated induction of FIG1 or lacZ, and repression of HHF1. Several cochaperone mutants tested had reduced FIG1 induction or HHF1 repression, although to differing extents. The greatest defects were in cpr7Delta, sse1Delta, and ydj1Delta mutants. Assays of Ste11 kinase activity revealed a pattern of defects in the cochaperone mutant strains that were similar to the gene expression studies. Overexpression of CDC37, a chaperone required for protein kinase folding, suppressed defects the sti1Delta mutant back to wild-type levels. CDC37 overexpression also restored stable Hsp90 binding to the Ste11 protein kinase domain in the sti1Delta mutant strain. These data suggest that Cdc37 and Sti1 have functional overlap in stabilizing Hsp90:client complexes. Finally, we show that Cns1 functions in MAP kinase signaling in association with Cpr7.
 ...
PMID:Sti1 and Cdc37 can stabilize Hsp90 in chaperone complexes with a protein kinase. 1474 21

Constitutive and induced protein SUMOylation is involved in the regulation of a variety of cellular processes, such as regulation of gene expression and protein transport, and proceeds mainly in the nucleus of the cell. So far, several hundred SUMOylation targets have been identified, but presumably they represent only a part of the total of proteins which are regulated by SUMOylation. Here, we used the Ubc9 fusion-dependent SUMOylation system (UFDS) to screen for constitutive and induced SUMOylation of 46 randomly chosen proteins with proven or potential nuclear localization. Fourteen new UFDS-substrate proteins were identified of which eight could be demonstrated to be SUMOylated in a UFDS-independent manner in vivo. Of these, three were constitutively SUMOylated (FOS, CRSP9 and CDC37) while the remaining five substrates (CSNK2B, TAF10, HSF2BP, PSMC3 and DRG1) showed a stimulation-dependent SUMOylation induced by the MAP3 kinase MEKK1. Hence, UFDS is appropriate for the identification and characterization of constitutive and, more importantly, induced protein SUMOylation in vivo.
 ...
PMID:Ubc9 fusion-directed SUMOylation identifies constitutive and inducible SUMOylation. 1770 45