Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1999-11-19
pubmed:abstractText
The quantitative expression of complement receptor type 1 (CR1) on erythrocytes is regulated by two CR1 alleles that differ in having genomic HindIII fragments of either 7.4 or 6.9 kb and that determine high (H allele) or low (L allele) CR1 expression, respectively, across a 10-fold range. To investigate whether the product of the L allele may contain amino acid substitutions that make it more susceptible to proteolysis, cDNA sequence spanning the CR1 coding region was analyzed in two donors who were homozygous for the H and L alleles and differed by 7-fold in their mean numbers of CR1 per erythrocyte. Sequence differences were detected at 10 nucleotide positions, including 6 that would cause amino acid substitutions. The HindIII RFLP and 3 of the latter 6 sites were analyzed in genomic DNA of 85 Caucasians and 75 African Americans; sites encoding the other amino acid substitutions were analyzed less extensively. Two major haplotypes defined prototypic H and L alleles in both ethnic groups, suggesting that these alleles existed before the African and European populations diverged. Decreased erythrocyte CR1 expression is associated with impaired clearance of immune complexes from blood. Persistence of the L allele in all populations that have been analyzed may suggest a compensatory survival advantage, perhaps related to malaria or another infectious disease.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
163
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4939-45
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Quantitative alleles of CR1: coding sequence analysis and comparison of haplotypes in two ethnic groups.
pubmed:affiliation
Department of Veterans Affairs Medical Center, Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S.