Estaller, C. and Koistinen, V. and Schwaeble, W. and Dierich, Manfred P. and Weiss, Elisabeth H.
CLONING OF THE 1.4-kb mRNA SPECIES OF HUMAN COMPLEMENT FACTOR H REVEALS A NOVEL MEMBER OF THE SHORT CONSENSUS REPEAT FAMILY RELATED TO THE CARBOXY TERMINAL OF THE CLASSICAL 150-kDa MOLECULE.
In: Journal of Immunology, Vol. 146: pp. 3190-3196
Three factor H mRNA species of 4.3 kb, 1.8 kb,
and 1.4 kb are constitutively expressed in human
liver. Having previously characterized full-length
cDNA clones derived from the 4.3-kb and 1.8-kb
factor mRNA, we report here the isolation and eucaryotic
expression of full-length cDNA clones coding
for the 1.4-kbm RNA species. The 1266-bp cDNA
codes for a polypeptide of 330 amino acids and
contains two polyadenylation signals and a short
poly(A)+tailT. he protein is composed of a leader
peptide followed by five short consensus repeat domains.
It shows a hybrid structure with the last
three domains being almost identical to the carboxy-
terminal of thcel assical 1 BO-kDa factor H molecule
and the two first domains representing unique
short consensus repeat structures. Eucaryotic
expression in COS7 cells revealed two polypeptides
derived from one cDNA clone that area lso found in
human serum. Differences between the cDcNloAn es
within the last three domains indicate two distinct,
possibly allelic sequences that, in addition, differ
from the authentic 150-kDa factor H sequence.
Southern blot results support the notion that the
4.3-kb factor H and the 1.4-kb factor H-related
mRNA are transcribed from two separate but highly
Factor H, a glycoprotein of 150,000