title: A point mutation of alanine 163 to threonine is responsible for the defective secretion of high molecular weight kininogen by the liver of brown Norway Katholiek rats.
abstract: To clarify the mechanism of the secretion defect of high molecular weight kininogen (HK) and low molecular weight kininogen (LK) by the liver of Brown Norway (B/N) Katholiek rats causing plasma kininogen deficiency, we cloned cDNAs for HK from cDNA libraries of the livers of B/N Katholiek and B/N Kitasato rats. A point mutation of G to A at nucleotide 487 was found in the cDNA of B/N Katholiek rats by sequence analysis of the cDNAs (including the entire HK-coding region) obtained from both strains. Both B/N Katholiek and B/N Kitasato rat cDNA fragments were introduced into a eukaryotic vector, pRc/CMV, to construct their respective expression plasmid, which was used to transfect COS-1 cells. At 24 h of incubation, the culture medium of COS-1 cells transfected with the B/N Katholiek rat cDNA contained only 10% of the HK antigen that was found in COS-1 cells transfected with the B/N Kitasato rat cDNA. More HK antigen was retained in the former cells. Moreover, cells transfected with B/N Katholiek rat cDNA, in which the A at nucleotide 487 was artificially replaced by G, secreted a significant amount of HK into the medium. These results suggest that a point mutation of G to A at nucleotide 487, which causes a substitution of Ala163 to Thr in the heavy chain of HK and LK, is responsible for the defective secretion of HK and LK by the liver of B/N Katholiek rats.
authors.affiliation: Department of Pharmacology, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Hayashi
authors.forename: S
authors.initials: S
authors.lastname: Hoshiko
authors.forename: O
authors.initials: O
authors.lastname: Makabe
authors.forename: S
authors.initials: S
authors.lastname: Oh-ishi
mesh_terms: D000409:Alanine / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA; D015342:DNA Probes; D007704:Kininogens / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000201:enzymology* / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids; D017354:Point Mutation; D051381:Rats; D011914:Rats, Inbred BN; D013912:Threonine / Q000378:metabolism; D014162:Transfection
chemical_list: D015342:DNA Probes; D007704:Kininogens; D013912:Threonine; D004247:DNA; D000409:Alanine