Linked Life Data

12000755

Source:http://linkedlifedata.com/resource/pubmed/id/12000755

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
2002-7-29
pubmed:abstractText
Mammalian target of rapamycin (mTOR) controls initiation of translation through regulation of ribosomal p70S6 kinase (S6K1) and eukaryotic translation initiation factor-4E (eIF4E) binding protein (4E-BP). mTOR is considered to be located predominantly in cytosolic or membrane fractions and may shuttle between the cytoplasm and nucleus. In most previous studies a single cell line, E1A-immortalized human embryonic kidney cells (HEK293), has been used. Here we show that in human malignant cell lines, human fibroblasts, and murine myoblasts mTOR is predominantly nuclear. In contrast, mTOR is largely excluded from the nucleus in HEK293 cells. Hybrids between HEK293 and Rh30 rhabdomyosarcoma cells generated cells co-expressing markers unique to HEK293 (E1A) and Rh30 (MyoD). mTOR distribution was mainly nuclear with detectable levels in the cytoplasm. mTOR isolated from Rh30 nuclei phosphorylated recombinant GST-4E-BP1 (Thr-46) in vitro and thus has kinase activity. We next investigated the cellular distribution of mTOR substrates 4E-BP, S6K1, and eIF4E. 4E-BP was exclusively detected in cytoplasmic fractions in all cell lines. S6K1 was localized in the cytoplasm in colon carcinoma, HEK293 cells, and IMR90 fibroblasts. S6K1 was readily detected in all cellular fractions derived from rhabdomyosarcoma cells. eIF4E was detected in all fractions derived from rhabdomyosarcoma cells but was not detectable in nuclear fractions from colon carcinoma HEK293 or IMR90 cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
28127-34
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Predominant nuclear localization of mammalian target of rapamycin in normal and malignant cells in culture.
pubmed:affiliation
Department of Molecular Pharmacology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-2794, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't