Earnest S, Khokhlatchev A, Albanesi J P, Barylko B
Department of Pharmacology, U.T. Southwestern Medical Center at Dallas, TX 75235-9041, USA.
FEBS Lett. 1996 Oct 28;396(1):62-6. doi: 10.1016/0014-5793(96)01074-5.
In the present study we show that purified bovine brain dynamin can be phosphorylated by MAP kinase, ERK2, with a stoichiometry of 1 mol phosphate/mol dynamin. The phosphorylated serine residue is located within the C-terminal 10 kDa of dynamin. Dynamin I phosphorylated by ERK2 can be specifically dephosphorylated by calcineurin but not by protein phosphatase 2A (PP2A). Phosphorylation of dynamin by ERK2 weakens the binding of dynamin to microtubules and inhibits dynamin's microtubule-activated GTPase activity. Stimulation of GTPase activity by either Grb2 or phospholipids was not affected by ERK2 phosphorylation, suggesting that the binding sites for Grb2 and phospholipids do not overlap with that for microtubules.
在本研究中，我们发现纯化的牛脑发动蛋白可被丝裂原活化蛋白激酶ERK2磷酸化，磷酸化化学计量比为1摩尔磷酸/摩尔发动蛋白。磷酸化的丝氨酸残基位于发动蛋白C末端10 kDa范围内。ERK2磷酸化的发动蛋白I可被钙调神经磷酸酶特异性去磷酸化，但不能被蛋白磷酸酶2A（PP2A）去磷酸化。ERK2对发动蛋白的磷酸化减弱了发动蛋白与微管的结合，并抑制了发动蛋白的微管激活型GTP酶活性。Grb2或磷脂对GTP酶活性的刺激不受ERK2磷酸化的影响，这表明Grb2和磷脂的结合位点与微管的结合位点不重叠。
