Distinct roles of PP1 and PP2A-like phosphatases in control of microtubule dynamics during mitosis.
Assembly of a mitotic spindle requires the accurate regulation of microtubule dynamics which is accomplished, at least in part, by phosphorylation-dephosphorylation reactions. Here we have investigated the role of serine-threonine phosphatases in the control of microtubule dynamics using specific inhibitors in Xenopus egg extracts. Type 2A phosphatases are required to maintain the short steady-state length of microtubules in mitosis by regulating the level of microtubule catastrophes, in part by controlling the the microtubule-destabilizing activity and phosphorylation of Op18/stathmin. Type 1 phosphatases are only required for control of microtubule dynamics during the transitions into and out of mitosis. Thus, although both type 2A and type 1 phosphatases are involved in the regulation of microtubule dynamics, they have distinct, non-overlapping roles.
Tournebize
R
R
Cell Biology Program, EMBL, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
Andersen
S S
SS
Verde
F
F
Dorée
M
M
Karsenti
E
E
Hyman
A A
AA
D000705:Anaphase; D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D008868:Microtubule Proteins; D008870:Microtubules / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D008938:Mitosis; D008954:Models, Biological; D019319:Okadaic Acid / Q000494:pharmacology; D009865:Oocytes / Q000502:physiology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D008941:Spindle Apparatus / Q000502:physiology / Q000648:ultrastructure; D050777:Stathmin; D014981:Xenopus; D029867:Xenopus Proteins
D007527:Isoenzymes; D008868:Microtubule Proteins; D010750:Phosphoproteins; C493996:STMN1 protein, Xenopus; C493995:STMN1 protein, human; D050777:Stathmin; D029867:Xenopus Proteins; D019319:Okadaic Acid; D016203:CDC2 Protein Kinase; D010749:Phosphoprotein Phosphatases