Linked Life Data

14674758

Source:http://linkedlifedata.com/resource/pubmed/id/14674758

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
50
pubmed:dateCreated
2003-12-16
pubmed:abstractText
Recently, we reported the first biochemical characterization of a novel member of the short-chain dehydrogenase/reductase superfamily, retinal reductase 1 (RalR1) (Kedishvili et al. (2002) J. Biol. Chem. 277, 28909-28915). In the present study, we purified the recombinant enzyme from the microsomal membranes of insect Sf9 cells, determined its catalytic efficiency for the reduction of retinal and the oxidation of retinol, established its transmembrane topology, and examined the distribution of RalR1 in human tissues and cell lines. Purified RalR1-His(6) exhibited the apparent K(m) values for all-trans-retinal and all-trans-retinol of 0.12 and 0.6 microM, respectively. The catalytic efficiency (k(cat)/K(m)) for the reduction of all-trans-retinal (150,000 min(-1) mM(-1)) was 8-fold higher than that for the oxidation of all-trans-retinol (18,000 min(-1) mM(-1)). Protease protection assays and site-directed mutagenesis suggested that the enzyme is anchored in the membrane by the N-terminal signal-anchor domain, with the majority of the polypeptide chain located on the cytosolic side of the membrane. An important feature that prevented the translocation of RalR1 across the membrane was the positively charged R(25)K motif flanking the N-terminal signal-anchor. The cytosolic orientation of RalR1 suggested that, in intact cells, the enzyme would function predominantly as a reductase. Western blot analysis revealed that RalR1 is expressed in a wide variety of normal human tissues and cancer cell lines. The expression pattern and the high catalytic efficiency of RalR1 are consistent with the hypothesis that RalR1 contributes to the reduction of retinal in various human tissues.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14838-45
pubmed:dateRevised
2008-9-4
pubmed:meshHeading
pubmed-meshheading:14674758-Alcohol Oxidoreductases, pubmed-meshheading:14674758-Amino Acid Sequence, pubmed-meshheading:14674758-Animals, pubmed-meshheading:14674758-Baculoviridae, pubmed-meshheading:14674758-Blotting, Western, pubmed-meshheading:14674758-Cell Line, pubmed-meshheading:14674758-Cell Line, Tumor, pubmed-meshheading:14674758-Humans, pubmed-meshheading:14674758-Intracellular Membranes, pubmed-meshheading:14674758-Kinetics, pubmed-meshheading:14674758-Membrane Proteins, pubmed-meshheading:14674758-Microsomes, pubmed-meshheading:14674758-Molecular Sequence Data, pubmed-meshheading:14674758-Organ Specificity, pubmed-meshheading:14674758-Oxidoreductases, pubmed-meshheading:14674758-Protein Structure, Tertiary, pubmed-meshheading:14674758-Recombinant Proteins, pubmed-meshheading:14674758-Spodoptera
pubmed:year
2003
pubmed:articleTitle
Properties of short-chain dehydrogenase/reductase RalR1: characterization of purified enzyme, its orientation in the microsomal membrane, and distribution in human tissues and cell lines.
pubmed:affiliation
Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, 64110, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.