Mnb/Dyrk1A phosphorylation regulates the interaction of dynamin 1 with SH3 domain-containing proteins.
Mnb/Dyrk1A is a proline-directed serine/threonine kinase implicated in Down's syndrome. Mnb/Dyrk1A was shown to phosphorylate dynamin 1 and alter its interactions with several SH3 domain-containing endocytic accessory proteins. To determine the mechanism of regulation, we mapped the Mnb/Dyrk1A phosphorylation sites in dynamin 1. Using a combination of deletion mutants and synthetic peptides, three potential Mnb/Dyrk1A phosphorylation sites (S778, S795, and S857) were first identified. Phosphorylation at S795 and S857 was confirmed in full-length dynamin 1, and S857 was subsequently determined to be the major Mnb/Dyrk1A phosphorylation site in vitro. Phosphorylation at S857 was demonstrated to be the basis for altering the binding of dynamin 1 to amphiphysin 1 and Grb 2 by site-directed mutants mimicking phosphorylation. Furthermore, S857 of dynamin 1 is phosphorylated by the endogenous kinase in brain extracts and in PC12 cells. In PC12 cells, the state of S857 phosphorylation is dependent on membrane potentials. These results suggest that S857 phosphorylation is a physiological event, which regulates the binding of dynamin 1 to SH3 domain-containing proteins. Since S857 is unique to dynamin 1xa isoforms, Mnb/Dyrk1A regulation of dynamin 1 is expected to be specific to these spliced variants.
Huang
Yu
Y
Molecular Biology Department, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA.
Chen-Hwang
Mo-Chou
MC
Dolios
Georgia
G
Murakami
Noriko
N
Padovan
Júlio C
JC
Wang
Rong
R
Hwang
Yu-Wen
YW
D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000818:Animals; D001666:Binding Sites, Antibody; D001921:Brain / Q000201:enzymology / Q000378:metabolism; D034284:Dynamin I / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004705:Endocytosis / Q000235:genetics; D051380:GRB2 Adaptor Protein; D018698:Glutamic Acid / Q000235:genetics; D013058:Mass Spectrometry; D016297:Mutagenesis, Site-Directed; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D016716:PC12 Cells; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D012694:Serine / Q000235:genetics / Q000378:metabolism; D018909:src Homology Domains; D019061:src-Family Kinases / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D000097603:Dyrk Kinases
D048868:Adaptor Proteins, Signal Transducing; D034284:Dynamin I; D051380:GRB2 Adaptor Protein; D018698:Glutamic Acid; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D011506:Proteins; D012694:Serine; D019061:src-Family Kinases; D000097603:Dyrk Kinases; C495950:Grb2 protein, rat; C075637:amphiphysin