Molecular cloning of cDNA for the carcinoma-associated antigen GA733-2.
Defined by monoclonal antibody GA733, the GA733-2 antigen is a cell surface 40-kDa glycoprotein associated with human carcinomas of various origins. Molecular clones for the GA733-2 antigen were isolated from a colorectal carcinoma cell line cDNA library using the high-efficiency COS cell expression system. A 1.4-kilobase cDNA species was enriched by immunoselection with monoclonal antibody. The authenticity of individual clones was established by immunologic and sequence criteria. At the amino acid sequence level, GA733-2 was found to be greater than 99% identical to the previously described KSA antigen defined by monoclonal antibody KS1/4. The amino acid sequence derived from the previously described GA733-related gene, GA733-1, was found to be 49% identical to GA733-2. The positions of 12 cysteine residues in the extracellular domains of the two GA733 antigens are conserved, as is the overall distribution of hydrophobic and hydrophilic residues. A 1.45-kilobase transcript of the GA733-2/KSA gene was found to be expressed in cell lines derived from colorectal and pancreatic carcinoma.
Szala
S
S
Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104.
Froehlich
M
M
Scollon
M
M
Kasai
Y
Y
Steplewski
Z
Z
Koprowski
H
H
Linnenbach
A J
AJ
D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics*; D001483:Base Sequence; D015815:Cell Adhesion Molecules; D002460:Cell Line; D003001:Cloning, Molecular; D015179:Colorectal Neoplasms; D004273:DNA, Neoplasm / Q000235:genetics*; D000071858:Epithelial Cell Adhesion Molecule; D015723:Gene Library; D006801:Humans; D015151:Immunoblotting; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D004273:DNA, Neoplasm; D000071858:Epithelial Cell Adhesion Molecule