Identification and characterization of a novel tyrosine kinase from megakaryocytes

• Published in: The Journal of biological chemistry Vol. 269; no. 2; pp. 1068 - 1074
• Main Authors: Bennett, B D, Cowley, S, Jiang, S, London, R, Deng, B, Grabarek, J, Groopman, J E, Goeddel, D V, Avraham, H
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 14-01-1994
• Subjects: amino acid sequence; Analytical, structural and metabolic biochemistry; Base Sequence; Biological and medical sciences; cDNA; Cloning, Molecular; Cytoplasm - enzymology; DNA Primers - chemistry; DNA, Complementary - genetics; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Gene Expression; genes; Humans; man; matk gene; megakaryocytes; Megakaryocytes - enzymology; Molecular Sequence Data; nucleotide sequence; platelets; predictions; protein-tyrosine kinase; Protein-Tyrosine Kinases - genetics; Proto-Oncogene Proteins pp60(c-src); RNA, Messenger - genetics; Sequence Alignment; Sequence Homology, Amino Acid; Tissue Distribution; Transferases; Human; Enzyme; Transferases; Megakaryocyte; Primary structure; Molecular cloning; Cell differentiation; Protein-tyrosine kinase
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(17)42222-8

Protein-tyrosine kinases play pivotal roles in cell signal transduction. We have isolated a cDNA clone encoding a novel human
intracytoplasmic tyrosine kinase, termed matk (megakaryocyte-associated tyrosine kinase). Expression of matk mRNA was predominantly
found in cells of megakaryocytic lineage. The matk cDNA clone encodes a polypeptide of 527 amino acids and has closest sequence
similarity to the csk tyrosine kinase. Sequence comparisons also indicate that matk contains src homology region 2 and 3 domains
but lacks the NH2-terminal myristylation signal, the negative regulatory tyrosine (Tyr-527), and the autophosphorylation site
(Tyr-416) corresponding to those found in src. Antibodies raised against the NH2 terminus of matk immunoprecipitated a 60-kDa
protein from the CMK human megakaryocyte cell line. Expression of matk mRNA was up-regulated in megakaryocytic cells induced
to differentiate by the phorbol ester. Based on its restriction in expression and its modulation during in vitro differentiation,
it is likely that matk participates in signal transduction during megakaryocytopoiesis.