Linked Life Data

9344464

Source:http://linkedlifedata.com/resource/pubmed/id/9344464

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-12-2
pubmed:databankReference
pubmed:abstractText
Long-chain fatty acids are the primary source of energy production in the heart. Carnitine palmitoyltransferase I (CPT-I) catalyzes the first reaction in the transport of long-chain fatty acids from the cytoplasm to the mitochondrion, a rate-limiting step in beta-oxidation. In this study, we report the functional expression of the human heart/skeletal muscle isoform of CPT-I (M-CPT-I) in the yeast Pichia pastoris. Screening of a human heart cDNA library with cDNA fragments encoding the rat heart M-CPT-I resulted in the isolation of a single full-length human heart M-CPT-I cDNA clone. The clone has an open reading frame of 2316 bp with a 5' untranslated region of 38 bp and a 256-bp 3' untranslated region with the poly(A)+ addition sequence AATAAA. The predicted protein has 772 amino acids and a molecular mass of 88 kDa. Northern blot analysis of mRNAs from different human tissues using the human M-CPT-I cDNA as a probe revealed an abundant transcript of approximately 3.1 kb that was only present in human heart and skeletal muscle tissue. Expression of the human M-CPT-I cDNA in P. pastoris, a yeast with no endogenous CPT activity, produced an 80-kDa protein that was located in the mitochondria. Isolated mitochondria from the M-CPT-I expression strain exhibited a malonyl-coenzyme A (CoA)-sensitive CPT activity that was detergent labile. The I50 for malonyl-CoA inhibition of the yeast-expressed M-CPT-I was 69 nM, and the Kms for carnitine and palmitoyl-CoA were 666 and 42 microM, respectively. The I50 for malonyl-CoA inhibition of the heart enzyme is 30 times lower than that of the yeast-expressed liver CPT-I, and the Km for carnitine is more than 20 times higher than that of the liver CPT-I. This is the first report of the expression of a heart CPT-I in a system devoid of endogenous CPT activity and the functional characterization of a human heart M-CPT-I in the absence of the liver isoform and CPT-II.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0003-9861
pubmed:author
pubmed:copyrightInfo
Copyright 1997 Academic Press. Copyright 1997Academic Press
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
347
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
53-61
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:9344464-Amino Acid Sequence, pubmed-meshheading:9344464-Animals, pubmed-meshheading:9344464-Base Sequence, pubmed-meshheading:9344464-Blotting, Northern, pubmed-meshheading:9344464-Carnitine, pubmed-meshheading:9344464-Carnitine O-Palmitoyltransferase, pubmed-meshheading:9344464-Cloning, Molecular, pubmed-meshheading:9344464-Gene Expression, pubmed-meshheading:9344464-Humans, pubmed-meshheading:9344464-Immunoblotting, pubmed-meshheading:9344464-Kinetics, pubmed-meshheading:9344464-Malonyl Coenzyme A, pubmed-meshheading:9344464-Mitochondria, pubmed-meshheading:9344464-Molecular Sequence Data, pubmed-meshheading:9344464-Myocardium, pubmed-meshheading:9344464-Palmitoyl Coenzyme A, pubmed-meshheading:9344464-Pichia, pubmed-meshheading:9344464-RNA, Messenger, pubmed-meshheading:9344464-Rats, pubmed-meshheading:9344464-Recombinant Proteins
pubmed:year
1997
pubmed:articleTitle
Functional studies of yeast-expressed human heart muscle carnitine palmitoyltransferase I.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Oregon Graduate Institute of Science and Technology, Portland, Oregon 97291-1000, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.