Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1984-7-2
pubmed:abstractText
Rabbit haptoglobin is a tetrameric protein consisting of two nonglycosylated alpha and two glycosylated beta chains, the latter being joined to the former and the former to each other by disulfide linkages. We describe here the results of studies that analyzed the biosynthetic pathway of rabbit haptoglobin by using cultured hepatocytes incubated with L-[35S]cysteine. The initial form of haptoglobin detected in hepatocytes exhibited Mr = 46,000, was glycosylated, and corresponded in migration to the initial species formed when the mRNA for rabbit haptoglobin was translated using the reticulocyte lysate system coupled with dog pancreatic microsomes. This one-chain intermediate was rapidly cleaved into a glycosylated form of the beta chain and into the mature alpha chain, these chains being joined by disulfide linkages. Dimerization also occurred rapidly, forming a tetrameric precursor of haptoglobin. Several other intracellular glycosylated forms of the beta chain were detected subsequently, representing intermediates formed during oligosaccharide processing prior to secretion of mature haptoglobin. Addition of tunicamycin (5 micrograms/ml) inhibited glycosylation of the initial form of haptoglobin detected, but subsequent proteolytic processing into alpha and beta chains still occurred. Our results showed that the pathway of biosynthesis of rabbit haptoglobin closely resembles that reported for rat haptoglobin ( Hanley , J. M., Haugen , T. H., and Heath, E. C. (1983) J. Biol. Chem. 258, 7858-7869).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6622-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Studies on the biosynthesis of rabbit haptoglobin.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't