Possible involvement of focal adhesion kinase, p125FAK, in osteoclastic bone resorption.
Involvement of tyrosine phosphorylation in osteoclastic bone resorption was examined using osteoclast-like multinucleated cells prepared from co-cultures of mouse osteoblastic cells and bone marrow cells in the presence of 1 alpha,25-dihydroxyvitamin D3. When osteoclast-like cells were plated on culture dishes in the presence of 10% fetal bovine serum, they were sharply stained in their peripheral region by anti-phosphotyrosine antibody. Western blot analysis revealed that 115- to 130-kD proteins were tyrosine-phosphorylated in osteoclast-like cells. Using immunoprecipitation and immunoblotting, one of the proteins with 115-130 kD was identified as focal adhesion kinase (p125FAK), a tyrosine kinase, which is localized in focal adhesions. Immunostaining with anti-p125FAK antibody revealed that p125FAK was mainly localized at the periphery of osteoclast-like cells. Herbimycin A, a tyrosine kinase inhibitor, not only suppressed tyrosine phosphorylation of p125FAK but also changed the intracellular localization of p125FAK and disrupted a ringed structure of F-actin-containing podosomes in osteoclast-like cells. Antisense oligodeoxynucleotides to p125FAK inhibited dentine resorption by osteoclast-like cells, whereas sense oligodeoxynucleotides did not. These results suggest that p125FAK is involved in osteoclastic bone resorption and that tyrosine phosphorylation of p125FAK is critical for regulating osteoclast function.
Tanaka
S
S
Department of Biochemistry, School of Dentistry, Showa University, Tokyo, Japan.
Takahashi
N
N
Udagawa
N
N
Murakami
H
H
Nakamura
I
I
Kurokawa
T
T
Suda
T
T
D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D016227:Benzoquinones; D001854:Bone Marrow Cells; D001862:Bone Resorption; D002117:Calcitriol / Q000494:pharmacology; D002417:Cattle; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000378:metabolism*; D002478:Cells, Cultured; D018920:Coculture Techniques; D003804:Dentin / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology; D007150:Immunohistochemistry; D047029:Lactams, Macrocyclic; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D010010:Osteoclasts / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D010750:Phosphoproteins / Q000032:analysis / Q000378:metabolism; D019000:Phosphotyrosine / Q000032:analysis; D011505:Protein-Tyrosine Kinases / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011809:Quinones / Q000494:pharmacology; D017828:Rifabutin / Q000031:analogs & derivatives; D013873:Thionucleotides
D016227:Benzoquinones; D015815:Cell Adhesion Molecules; D004791:Enzyme Inhibitors; D047029:Lactams, Macrocyclic; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D010750:Phosphoproteins; D011809:Quinones; D013873:Thionucleotides; D017828:Rifabutin; D019000:Phosphotyrosine; C020754:herbimycin; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496051:Ptk2 protein, mouse; D002117:Calcitriol