QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sumiyoshi, E. Articles by Yamamoto, M. Search for Related Content PubMed PubMed Citation Articles by Sumiyoshi, E. Articles by Yamamoto, M. Social Bookmarking                         What's this?

Protein phosphatase 4 is required for centrosome maturation in mitosis and sperm meiosis in C. elegans

¹ Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Hongo, Tokyo 113-0033, Japan
² PRESTO, Japan Science and Technology Corporation, Kawaguchi, Saitama 332-0012, Japan
³ Laboratory for Developmental Genomics, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan

^* Author for correspondence (e-mail: myamamot{at}ims.u-tokyo.ac.jp )

Accepted 6 January 2002

The centrosome consists of two centrioles surrounded by the pericentriolar material (PCM). In late G2 phase, centrosomes enlarge by recruiting extra PCM, and concomitantly its microtubule nucleation activity increases dramatically. The regulatory mechanisms of this dynamic change of centrosomes are not well understood. Protein phosphatase 4 (PP4) is known to localize to mitotic centrosomes in mammals and Drosophila. An involvement of PP4 in the mitotic spindle assembly has been implicated in Drosophila, but in vivo functions of PP4 in other organisms are largely unknown. Here we characterize two Caenorhabditis elegans PP4 genes, named pph-4.1 and pph-4.2. Inhibition of the function of each gene by RNA-mediated interference (RNAi) revealed that PPH-4.1 was essential for embryogenesis but PPH-4.2 was not. More specifically, PPH-4.1 was required for the formation of spindles in mitosis and sperm meiosis. However, this phosphatase was apparently dispensable for female meiotic divisions, which do not depend on centrosomes. In the cell depleted of pph-4.1 activity, localization of -tubulin and a Polo-like kinase homologue to the centrosome was severely disturbed. Immunofluorescence staining revealed that PPH-4.1 was present at centrosomes from prophase to telophase, but not during interphase. These results indicate that PPH-4.1 is a centrosomal protein involved in the recruitment of PCM components to the centrosome, and is essential for the activation of microtubule nucleation potential of the centrosome. Furthermore, chiasmata between homologous chromosomes were often absent in oocytes that lacked pph-4.1 activity. Thus, besides promoting spindle formation, PPH-4.1 appears to play a role in either the establishment or the maintenance of chiasmata during meiotic prophase I.

Key words: C. elegans, PP4, Centrosome, -Tubulin, Spindle assembly, Chiasma, Meiosis

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				X. Han, J.-E. Gomes, C. L. Birmingham, L. Pintard, A. Sugimoto, and P. E. Mains The Role of Protein Phosphatase 4 in Regulating Microtubule Severing in the Caenorhabditis elegans Embryo Genetics, March 1, 2009; 181(3): 933 - 943. [Abstract] [Full Text] [PDF]

				R. Sousa-Nunes, W. Chia, and W. G. Somers Protein Phosphatase 4 mediates localization of the Miranda complex during Drosophila neuroblast asymmetric divisions Genes & Dev., February 1, 2009; 23(3): 359 - 372. [Abstract] [Full Text] [PDF]

				D. M. Rivers, S. Moreno, M. Abraham, and J. Ahringer PAR proteins direct asymmetry of the cell cycle regulators Polo-like kinase and Cdc25 J. Cell Biol., March 5, 2008; 180(5): 877 - 885. [Abstract] [Full Text] [PDF]

				S.-H. Kim, A. H. Holway, S. Wolff, A. Dillin, and W. M. Michael SMK-1/PPH-4.1 mediated silencing of the CHK-1 response to DNA damage in early C. elegans embryos J. Cell Biol., October 8, 2007; 179(1): 41 - 52. [Abstract] [Full Text] [PDF]

				M. C. Mendoza, E. O. Booth, G. Shaulsky, and R. A. Firtel MEK1 and Protein Phosphatase 4 Coordinate Dictyostelium Development and Chemotaxis Mol. Cell. Biol., May 15, 2007; 27(10): 3817 - 3827. [Abstract] [Full Text] [PDF]

				B. A. Buckley, A. Y. Gracey, and G. N. Somero The cellular response to heat stress in the goby Gillichthys mirabilis: a cDNA microarray and protein-level analysis J. Exp. Biol., July 15, 2006; 209(14): 2660 - 2677. [Abstract] [Full Text] [PDF]

				C. N. Hancock, S. Dangi, and P. Shapiro Protein Phosphatase 2A Activity Associated with Golgi Membranes during the G2/M Phase May Regulate Phosphorylation of ERK2 J. Biol. Chem., March 25, 2005; 280(12): 11590 - 11598. [Abstract] [Full Text] [PDF]

				G. Zhou, J. S. Boomer, and T.-H. Tan Protein Phosphatase 4 Is a Positive Regulator of Hematopoietic Progenitor Kinase 1 J. Biol. Chem., November 19, 2004; 279(47): 49551 - 49561. [Abstract] [Full Text] [PDF]

				K. A. Mihindukulasuriya, G. Zhou, J. Qin, and T.-H. Tan Protein Phosphatase 4 Interacts with and Down-regulates Insulin Receptor Substrate 4 following Tumor Necrosis Factor-{alpha} Stimulation J. Biol. Chem., November 5, 2004; 279(45): 46588 - 46594. [Abstract] [Full Text] [PDF]

				G. K. Carnegie, J. E. Sleeman, N. Morrice, C. J. Hastie, M. W. Peggie, A. Philp, A. I. Lamond, and P. T. W. Cohen Protein phosphatase 4 interacts with the Survival of Motor Neurons complex and enhances the temporal localisation of snRNPs J. Cell Sci., May 15, 2003; 116(10): 1905 - 1913. [Abstract] [Full Text] [PDF]