Phosphorylation of mouse LASP-1 on threonine 156 by cAMP- and cGMP-dependent protein kinase.
LIM and SH3 domain protein (LASP-1) is a specific focal adhesion protein involved in cell migration. Overlay studies demonstrate that LASP-1 directly binds to the proline-rich domains of zyxin, lipoma preferred partner (LPP), and vasodilator-stimulated phosphoprotein (VASP), with zyxin being the most prominent interacting partner. Despite the LIM/zinc-finger domain, hypothesized to be involved in homodimerization, LASP-1 exists as a monomer. In vitro phosphorylation of recombinant mouse LASP-1 by cAMP- and cGMP-dependent protein kinase (PKA and PKG, respectively) occurs at serine 61, serine 99, and threonine 156 whereas in intact cells mouse LASP-1 is phosphorylated only at threonine 156. This site is different from the known in vivo phosphorylation sites in human (serine 146) and rabbit (serine 99 and serine 146). Nevertheless, immunofluorescence of LASP-1 in human and mouse mesangial cells revealed no difference in subcellular distribution. Exposure of the cells to forskolin induced a translocation of both, human and mouse LASP-1, from the focal contacts to the cell interior without affecting F-actin structure. Immunoblotting of LASP-1 in various mouse and human tissues detected a similar prominent expression in non-muscle tissue. Altogether, our data suggest so far no functional differences between human and mouse LASP-1.
Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Josef-Schneider-Str. 2, D-97080 Würzburg, Germany.
Christian
C
Keicher
Stepan
S
Gambaryan
Elfriede
E
Schulze
Katrin
K
Marcus
Helmut E
HE
Meyer
Elke
E
Butt
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005920:Glomerular Mesangium / Q000166:cytology / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D060588:LIM Domain Proteins; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011487:Protein Conformation; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013912:Threonine / Q000378:metabolism*; D014018:Tissue Distribution; D060589:Zyxin; D000098662:Vasodilator-Stimulated Phosphoprotein
D000199:Actins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D018398:Homeodomain Proteins; D060588:LIM Domain Proteins; C103594:LPP protein, human; C490692:Lasp1 protein, mouse; D008840:Microfilament Proteins; D009363:Neoplasm Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; C092842:ZYX protein, human; D060589:Zyxin; D000098662:Vasodilator-Stimulated Phosphoprotein; D013912:Threonine; D017868:Cyclic AMP-Dependent Protein Kinases; D017869:Cyclic GMP-Dependent Protein Kinases