title: Colon carcinoma kinase-4 defines a new subclass of the receptor tyrosine kinase family.
abstract: Complementary DNA (cDNA) encoding a novel member of the receptor tyrosine kinase (RTK) family has been isolated from colon carcinoma tissue. Colon carcinoma kinase 4 (CCK-4) mRNA is highly expressed in human lung tissue and at lower levels in the thyroid gland and ovary. While no mRNA was found in human adult colon tissues, expression varied remarkably in colon carcinoma-derived cell lines. CCK-4 cDNA encodes a chicken KLG-related, 1071 amino acid-long transmembrane glycoprotein containing several genetic alterations within the RTK consensus sequences. These define CCK-4 as a catalytically inactive member of the RTK family of proteins and, in analogy to HER3, suggest a potentially tumor-characteristic role as a signal amplifier or modulator for an as yet unidentified kinase-competent partner.
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D015815:Cell Adhesion Molecules; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000235:genetics; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D004277:DNA, Single-Stranded / Q000032:analysis / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis / Q000145:classification / Q000235:genetics*; D014162:Transfection
chemical_list: D015815:Cell Adhesion Molecules; D004273:DNA, Neoplasm; D004277:DNA, Single-Stranded; D009363:Neoplasm Proteins; D012333:RNA, Messenger; C096905:PTK7 protein, human; D020794:Receptor Protein-Tyrosine Kinases