Nucleotide sequence of cDNA encoding human alpha 2-macroglobulin and assignment of the chromosomal locus.

Abstract

Six .alpha.2-macroglobulin (.alpha.2M) cDNA [complementary DNA] clones were isolated from a human liver cDNA library by using synthetic oligonucleotides as hybridization probes. One of these, p.alpha.2M1, carries a 4.6-kilobase-pair insert, which was sequenced. The insert contains the coding sequences for the mature .alpha.2M polypeptide (1451 amino acids) and for a 23-amino acid signal peptide at the NH2 terminus of the precursor pro-.alpha.2M. At the 3'' end of the insert a poly(A) addition signal A-A-T-A-A-A and part of the poly(A) tail of the messenger RNA were found. The protein sequence deduced from the nucleotide sequence agrees with the published .alpha.2M amino acid sequence for all except 3 residues. The .alpha.2M locus was assigned to human chromosome 12 by Southern blot analysis with DNA from a panel of mouse/human somatic cell hybrids, using .alpha.2M cDNA as a hybridization probe.