Estaller, Cornelia; Schwaeble, Wilhelm; Dierich, Manfred P.; Weiss, Elisabeth H.
Human complement factor H. Two factor H proteins are derived from alternatively spliced transcripts.
In: European Journal of Immunology, Vol. 21: S. 799-802
The human complement factor H is an important component in the control of the
alternative pathway of complement activation. We have previously shown that at
least three factor H homologous mRNA species of 4.3 kb, 1.8 kb and 1.4 kb in
length are constitutively expressed in human liver. In addition, several factor Hrelated
proteins have been detected in human sera using antibodies directed
against the classical human factor H glycoprotein of 150 kDa.The structure of the
additional polypeptides has not been shown so far. Circumstantial evidence
suggests that the 1.8-kb mRNA might encode the 43-kDa factor H-like
polypeptide. Here we report the isolation, characterization and eukaryotic
expression of the first full-length cDNA representing the major 4.3-kb mRNA
and the 1.8-kb mRNA of human factor H. We show that the 4.3-kb transcript
encodes the 150-kDa-factor H glycoprotein and the 1.8-kb mRNA the 43-kDa
factorH polypeptide. The identity of the two cDNA in a region of 1400
nucleotides suggests that the two factor H-related transcripts are derived from
one gene by a process of alternative splicing.