Cloning and characterization of Dfak56, a homolog of focal adhesion kinase, in Drosophila melanogaster.
The focal adhesion kinase (FAK) protein-tyrosine kinase plays important roles in cell adhesion in vertebrates. Using polymerase chain reaction-based cloning strategy, we cloned a Drosophila gene that is homologous to the vertebrate FAK family of protein-tyrosine kinases. We designated this gene Dfak56 and characterized its gene product. The overall protein structure and deduced amino acid sequence of Dfak56 show significant similarity to those of FAK and PYK2. Dfak56 has in vitro autophosphorylation activity at tyrosine residues. Expression of the Dfak56 mRNA and the protein was observed in the central nervous system and the muscle-epidermis attachment site in the embryo, where Drosophila position-specific integrins are localized. The results suggest that like FAK in vertebrates, Dfak56 functions downstream of integrins. Dfak56 was tyrosine-phosphorylated upon integrin-dependent attachment of the cell to the extracellular matrix. We conclude that the Dfak56 tyrosine kinase is involved in integrin-mediated cell adhesion signaling and thus is a functional homolog of vertebrate FAK.
Fujimoto
J
J
Department of Oncology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan.
Sawamoto
K
K
Okabe
M
M
Takagi
Y
Y
Tezuka
T
T
Yoshikawa
S
S
Ryo
H
H
Okano
H
H
Yamamoto
T
T
D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000235:genetics*; D003001:Cloning, Molecular; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000201:enzymology*; D005109:Extracellular Matrix / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D017403:In Situ Hybridization; D016023:Integrins / Q000378:metabolism; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000032:analysis; D011505:Protein-Tyrosine Kinases / Q000737:chemistry* / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction
D015815:Cell Adhesion Molecules; D029721:Drosophila Proteins; D016023:Integrins; D010750:Phosphoproteins; D012333:RNA, Messenger; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases; C496049:Fak protein, Drosophila; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases