Linked Life Data

3292527

Source:http://linkedlifedata.com/resource/pubmed/id/3292527

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
1988-8-19
pubmed:abstractText
Insulin binding to rat liver plasma membranes promotes proteolysis of the Mr 135,000 alpha subunit of the insulin receptor to a fragment of Mr 120,000 (Lipson, K. E., Yamada, K., Kolhatkar, A. A., and Donner, D. B. (1986) J. Biol. Chem. 261, 10833-10838). The enzyme that catalyzes this degradation copurifies with plasma membranes and cannot be identified in any other cellular organelle or in cytosol. The proteinase has optimal activity above pH 7 and is an integral protein based upon its resistance to extraction with 2 M NaCl. After affinity labeling, degraded insulin receptors were identified in plasma membranes isolated from a liver perfused with 1 nM 125I-insulin for 10 min at 37 degrees C, indicating that proteolysis occurs in the hepatocyte cell membrane under physiological conditions. Microsomes do not contain the receptor degrading activity or a detectable amount of degraded receptors under basal conditions. After perfusion of a liver with 125I-insulin, Mr 135,000 and Mr 120,000 complexes were detected in microsomes, suggesting that both intact and degraded receptors can be internalized. The initial absence of degraded receptors in plasma membranes suggests that, following internalization, such sites do not recycle. Thus, hormone-induced proteolysis of the insulin receptor begins at the surface of the rat hepatocyte and can lead to loss of receptors from the plasma membrane.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10495-501
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Cell surface proteolysis and down-regulation of the hepatic insulin receptor. Evidence for selective sorting of intact and degraded receptors after internalization.
pubmed:affiliation
Memorial Sloan-Kettering Cancer Center, New York, New York 10021.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't