Structural and Functional Studies of the Intracellular Tyrosine Kinase MATK Gene and Its Translated Product

doi:10.1074/jbc.270.4.1833

Structural and Functional Studies of the Intracellular Tyrosine Kinase MATK Gene and Its Translated Product (*)

From the Division of Hematology/Oncology, New England Deaconess Hospital, Harvard Medical School, Boston, Massachusetts 02215 and the Section of Genetics, Children's Mercy Hospital, UMKC School of Medicine, Kansas City, Missouri 64108

^§ To whom correspondence should be addressed:
Div. of Hematology/Oncology, New England Deaconess Hospital, One Deaconess Rd., Boston, MA 02215
. Tel.: 617-632-0119; Fax: 617-424-6237.

Abstract

We recently cloned the cDNA which encodes a novel megakaryocyte-associated tyrosine kinase termed MATK. In this study, we have cloned and characterized the human MATK gene as well as the murine homolog of human MATK cDNA and performed functional studies of its translated product. Comparison of the deduced amino acid sequences of human and murine MATK cDNAs revealed 85% homology, indicating that MATK is highly conserved in mouse and human. The human gene consists of 13 exons interrupted by 12 introns. The genetic units which encode the SH3 and SH2 domains are located on separate exons. The putative ATP binding site (GXGXXG) is localized on exon 7, and the entire catalytic domain is subdivided into seven exons(7, 8, 9, 10, 11, 12, 13). Somatic cell hybrid analysis indicated that human MATK gene is located on chromosome 19 while the murine Matk gene is located on chromosome 10. The immediate 5′-flanking region was highly rich in GC sequences, and potential cis-acting elements were identified including several SP1, GATA-1, APRE, and APRE1. Antisense oligonucleotides directed against MATK mRNA sequences significantly inhibited megakaryocyte progenitor proliferation. Functional studies indicated that MATK can phosphorylate the carboxyl-terminal conserved tyrosine of the Src protein. These results support the notion that MATK acts as a regulator of p60 in megakaryocytic cells and participates in the pathways regulating growth of cells of this lineage.

Footnotes

↵* This work was supported in part by National Institutes of Health Grants R01 HL51456 and R01 HL46668. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

MATK

megakaryocyte-associated tyrosine kinase

PTK

protein tyrosine kinase

SH

Src homology

PCR

polymerase chain reaction

PPP

platelet-poor plasma

P/S

penicillin/streptomycin

PMA

phorbol 12-myristate 13-acetate

GpIIIa

glycoprotein IIIa

RFLP

restriction fragment length polymorphism

bp

base pair(s)

kb

kilobase(s)

PAGE

polyacrylamide gel electrophoresis

FSBA

5-(p-fluorosulfonylbenzoyl) adenosine.
- Received June 21, 1994.
- Revision received October 14, 1994.