Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2004-5-10
pubmed:abstractText
The tuberous sclerosis gene products Tsc1 and Tsc2 behave as tumor suppressors by restricting cell growth, a function conserved among metazoans. Recent evidence has indicated that hyperactivation of S6 kinase 1 (S6K1) may represent an important biochemical change in the development of tuberous sclerosis-associated lesions. We show here that deletion of either Tsc1 or Tsc2 or expression of the Rheb (Ras homolog enriched in brain) GTPase leads to hyperphosphorylation of S6K1 at a subset of regulatory sites, particularly those of two essential residues functionally conserved among AGC superfamily serine/threonine kinases, i.e. the activation loop (T-loop; Thr-229) and the hydrophobic motif (H-motif; Thr-389). These sites are reciprocally and dose-dependently regulated when S6K1 is coexpressed with the Tsc1-Tsc2 complex. Mutations that render S6K1 mTOR (mammalian target of rapamycin)-resistant also protect S6K1 activity and phosphorylation from down-regulation by Tsc1/2. We demonstrate that two disease-associated mutations in Tsc2 fail to negatively regulate S6K1 activity concomitant with a failure to modify T-loop and H-motif phosphorylation. Finally, we identify one pathological Tsc2 mutation that retains its ability to negatively regulate S6K1, suggesting that, in some cases, tuberous sclerosis may develop independently of S6K1 hyperactivation. These results also highlight the importance of dual control of T-loop and H-motif phosphorylation of S6K1 by the Tsc1-Tsc2 complex.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Androstadienes, http://linkedlifedata.com/resource/pubmed/chemical/CCL26 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Chemokines, CC, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Insulin, http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments, http://linkedlifedata.com/resource/pubmed/chemical/Repressor Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Ribosomal Protein S6 Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Sirolimus, http://linkedlifedata.com/resource/pubmed/chemical/Tumor Suppressor Proteins, http://linkedlifedata.com/resource/pubmed/chemical/tuberous sclerosis complex 2 protein, http://linkedlifedata.com/resource/pubmed/chemical/wortmannin
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20816-23
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:14993219-Amino Acid Sequence, pubmed-meshheading:14993219-Androstadienes, pubmed-meshheading:14993219-Animals, pubmed-meshheading:14993219-Cell Line, pubmed-meshheading:14993219-Chemokines, CC, pubmed-meshheading:14993219-Enzyme Activation, pubmed-meshheading:14993219-Enzyme Inhibitors, pubmed-meshheading:14993219-Gene Expression Regulation, Enzymologic, pubmed-meshheading:14993219-Humans, pubmed-meshheading:14993219-Insulin, pubmed-meshheading:14993219-Mice, pubmed-meshheading:14993219-Peptide Fragments, pubmed-meshheading:14993219-Phosphorylation, pubmed-meshheading:14993219-Rabbits, pubmed-meshheading:14993219-Rats, pubmed-meshheading:14993219-Repressor Proteins, pubmed-meshheading:14993219-Ribosomal Protein S6 Kinases, pubmed-meshheading:14993219-Sirolimus, pubmed-meshheading:14993219-Transfection, pubmed-meshheading:14993219-Tuberous Sclerosis, pubmed-meshheading:14993219-Tumor Suppressor Proteins
pubmed:year
2004
pubmed:articleTitle
Critical role of T-loop and H-motif phosphorylation in the regulation of S6 kinase 1 by the tuberous sclerosis complex.
pubmed:affiliation
Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't