Structure and expression of novel protein-tyrosine kinases, Emb and Emt, in hematopoietic cells.
Two novel tyrosine kinase cDNAs were obtained from murine mast cells. These kinases, Emb and Emt, constitute a novel tyrosine kinase subfamily which may also include Tec, a kinase preferentially expressed in liver, and Dsrc28, a fruit fly kinase. Both lack hydrophobic stretches characteristic of the transmembrane domains found in growth factor receptor tyrosine kinases and carboxyl-terminal, negative regulatory tyrosine residue found in Src family kinases. In addition to the Src homology region 2 (SH2) and SH3 domains characteristic of the Src family kinases and other signaling molecules, Emb and Emt share a similar amino-terminal domain comprised mainly of two repeat segments. The emb 2.7-kb transcript was expressed in mast cells, myeloid cells and B lymphocytes while the emt 4.6-kb mRNA in mast cells, myeloid cells and T lymphocytes. The evidence for in vitro tyrosine kinase activity of Emb and Emt proteins is also provided.
Yamada
N
N
Division of Immunobiology, La Jolla Institute for Allergy and Immunology, California 92037.
Kawakami
Y
Y
Kimura
H
H
Fukamachi
H
H
Baier
G
G
Altman
A
A
Kato
T
T
Inagaki
Y
Y
Kawakami
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004277:DNA, Single-Stranded; D008407:Mast Cells / Q000201:enzymology*; D051379:Mice; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014443:Tyrosine / Q000378:metabolism
D004277:DNA, Single-Stranded; D012333:RNA, Messenger; D014443:Tyrosine; C080812:emb protein-tyrosine kinase; D011505:Protein-Tyrosine Kinases; C080813:emt protein-tyrosine kinase