Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0024141 (
systemic lupus erythematosus
)
44,322
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Complement receptor type 1
(
CR1
) is a glycoprotein of Mr about 250 000 present on erythrocytes and other cell types.
CR1
acts as a cofactor in the factor I-mediated breakdown of complement fragment C3b to form iC3b. Using an assay of cofactor activity, a wide variation in mean
CR1
levels between erythrocytes from individual donors is observed.
CR1
levels also decrease on ageing of erythrocytes in vivo, and again the rate of loss is widely variable between individuals. However, variable loss of
CR1
during ageing of erythrocytes is likely to make only a minor contribution to the observed variation in mean
CR1
levels.
CR1
is very sensitive to proteolysis, and random proteolytic removal of
CR1
from erythrocytes is likely to be an important factor in loss of
CR1
on ageing of red cells in vivo. In vitro, mild trypsin treatment, plasmin or thrombin digestion of erythrocytes results in the loss of the factor I cofactor activity from the cell surface, and appearance of this activity in the supernatant. We conclude that an active fragment of
CR1
is released from the cell surface on proteolysis. Subsequent prolonged trypsin treatment destroys most of the activity of this fragment. Proteolytic removal of
CR1
from red cells may account not only for loss on ageing of cells, but also for the acquired
CR1
deficiencies observed by others in
systemic lupus erythematosus
.
...
PMID:Loss of complement receptor type 1 (CR1) on ageing of erythrocytes. Studies of proteolytic release of the receptor. 294 10
