Linked Life Data

8132643

Source:http://linkedlifedata.com/resource/pubmed/id/8132643

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1994-4-21
pubmed:abstractText
High plasma levels of lipoprotein(a) (Lp(a)) and its unique apolipoprotein, apo(a), are an independent risk factor for cardiovascular disease. Plasma Lp(a) levels vary over a 1000-fold range and are determined by the apo(a) locus, which has at least 34 alleles expressing apo(a) isoforms with molecular weights from < 300,000 to > 800,000. In addition, "null" apo(a) alleles produce no detectable plasma apo(a). We used primary cultures of baboon hepatocytes to investigate the molecular basis for null apo(a) phenotypes. Immunoprecipitation of apo(a) after radiolabeling of hepatocytes revealed that some null alleles gave rise to intracellular protein products that were not secreted. Pulse-chase analysis and endoglycosidase digests demonstrated that these proteins were retained in the endoplasmic reticulum. We also examined the molecular basis for the documented inverse correlation between apo(a) size and plasma Lp(a) concentration. Steady-state labeling and pulse-chase analysis of hepatocytes from animals expressing two isoforms of apo(a) revealed that the endoplasmic reticulum residence time of secreted apo(a) isoforms was determined by their size. This accounted for the inverse relationship between isoform size and level of secretion. We conclude that the efficiency of post-translational processing of apo(a) is a major determinant of plasma Lp(a) concentration.
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
25
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9060-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Molecular basis for "null" lipoprotein(a) phenotypes and the influence of apolipoprotein(a) size on plasma lipoprotein(a) level in the baboon.
pubmed:affiliation
Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, Texas 78228-0147.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.