PMID- 10528197
OWN - NLM
STAT- MEDLINE
DCOM- 19991119
LR  - 20061115
IS  - 0022-1767 (Print)
IS  - 0022-1767 (Linking)
VI  - 163
IP  - 9
DP  - 1999 Nov 1
TI  - Quantitative alleles of CR1: coding sequence analysis and comparison of
      haplotypes in two ethnic groups.
PG  - 4939-45
AB  - 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.
FAU - Xiang, L
AU  - Xiang L
AD  - Department of Veterans Affairs Medical Center, Department of Medicine, University
      of Mississippi Medical Center, Jackson 39216, USA.
FAU - Rundles, J R
AU  - Rundles JR
FAU - Hamilton, D R
AU  - Hamilton DR
FAU - Wilson, J G
AU  - Wilson JG
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - J Immunol
JT  - Journal of immunology (Baltimore, Md. : 1950)
JID - 2985117R
RN  - 0 (Receptors, Complement 3b)
SB  - AIM
SB  - IM
MH  - African Continental Ancestry Group/*genetics
MH  - *Alleles
MH  - Amino Acid Substitution/genetics/immunology
MH  - European Continental Ancestry Group/*genetics
MH  - Haplotypes/*immunology
MH  - Humans
MH  - Polymorphism, Restriction Fragment Length
MH  - Receptors, Complement 3b/*chemistry/*genetics/isolation & purification
MH  - Reverse Transcriptase Polymerase Chain Reaction
MH  - Sequence Analysis, DNA
EDAT- 1999/10/21 00:00
MHDA- 1999/10/21 00:01
CRDT- 1999/10/21 00:00
PHST- 1999/10/21 00:00 [pubmed]
PHST- 1999/10/21 00:01 [medline]
PHST- 1999/10/21 00:00 [entrez]
AID - ji_v163n9p4939 [pii]
PST - ppublish
SO  - J Immunol. 1999 Nov 1;163(9):4939-45.