Linked Life Data

11108711

Source:http://linkedlifedata.com/resource/pubmed/id/11108711

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2001-5-25
pubmed:abstractText
Ribosomal S6 kinase (S6K1), through phosphorylation of the 40 S ribosomal protein S6 and regulation of 5'-terminal oligopyrimidine tract mRNAs, is an important regulator of cellular translational capacity. S6K1 has also been implicated in regulation of cell size. We have recently identified S6K2, a homolog of S6K1, which phosphorylates S6 in vitro and is regulated by the phosphatidylinositide 3-kinase (PI3-K) and mammalian target of rapamycin pathways in vivo. Here, we characterize S6K2 regulation by PI3-K signaling intermediates and compare its regulation to that of S6K1. We report that S6K2 is activated similarly to S6K1 by the PI3-K effectors phosphoinositide-dependent kinase 1, Cdc42, Rac, and protein kinase Czeta but that S6K2 is more sensitive to basal activation by myristoylated protein kinase Czeta than is S6K1. The C-terminal sequence of S6K2 is divergent from that of S6K1. We find that the S6K2 C terminus plays a greater role in S6K2 regulation than does the S6K1 C terminus by functioning as a potent inhibitor of activation by various agonists. Removal of the S6K2 C terminus results in an enzyme that is hypersensitive to agonist-dependent activation. These data suggest that S6K1 and S6K2 are similarly activated by PI3-K effectors but that sequences unique to S6K2 contribute to stronger inhibition of its kinase activity. Understanding the regulation of the two S6K homologs may provide insight into the physiological roles of these kinases.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7884-91
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Regulation of ribosomal S6 kinase 2 by effectors of the phosphoinositide 3-kinase pathway.
pubmed:affiliation
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't