Clathrin light chain b is capable of affecting potently a major protein phosphatase from microtubules (MT-PP1).
Clathrin light chain (CL) b purified from bovine brain postmicrotubule supernatant and identified by mass spectrometry potently inhibited a catalytic activity of a major protein phosphatase (PP) that was copurified with microtubules and recognized by antiPP1 antibodies. CLb similarly affected the catalytic subunit and holoenzyme of the PP, little inhibiting the activity of PP2A. Although the CLb from clathrin-coated vesicles was several hundredfold weaker than our purified CLb, the CLb in the postmicrotubule supernatant, independent of whether it was sedimentable or soluble, was as active as the purified CLb. Thus CLb may be a potent regulator of the PP.
Hiraga
Akira
A
Department of Biochemistry, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryomachi, Aobaku, Sendai 980-8575, Japan. hiraga@idac.tohoku.ac.jp
Morrice
Nick
N
Honda
Eiko
E
Tamura
Shinri
S
Munakata
Hiroshi
H
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D033941:Clathrin Light Chains / Q000302:isolation & purification / Q000494:pharmacology*; D022163:Clathrin-Coated Vesicles; D013058:Mass Spectrometry; D008868:Microtubule Proteins / Q000037:antagonists & inhibitors*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors*; D054648:Protein Phosphatase 2; D012995:Solubility
D033941:Clathrin Light Chains; D008868:Microtubule Proteins; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2