QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 17, Issue 1, 14-24, January 2006

This Article Full Text Full Text (PDF) Supplemental Material All Versions of this Article: E05-06-0548v1 17/1/14    most recent Alert me when this article is cited Alert me if a correction is posted Services 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 Paronetto, M. P. Articles by Sette, C. Search for Related Content PubMed PubMed Citation Articles by Paronetto, M. P. Articles by Sette, C.

The Nuclear RNA-binding Protein Sam68 Translocates to the Cytoplasm and Associates with the Polysomes in Mouse Spermatocytes

Maria Paola Paronetto ^* , Francesca Zalfa , Flavia Botti ^*, Raffaele Geremia ^*, Claudia Bagni  , and Claudio Sette ^* 

^* Department of Public Health and Cell Biology, Section of Anatomy, University of Rome "Tor Vergata," 00133 Rome, Italy; Department of Biology, University of Rome "Tor Vergata," 00133 Rome, Italy; and Institute of Experimental Neuroscience, Fondazione Santa Lucia IRCCS, 00179 Rome, Italy

Submitted June 20, 2005; Revised September 15, 2005; Accepted October 5, 2005
Monitoring Editor: Joseph Gall

Translational control plays a crucial role during gametogenesis in organisms as different as worms and mammals. Mouse knockout models have highlighted the essential function of many RNA-binding proteins during spermatogenesis. Herein we have investigated the expression and function during mammalian male meiosis of Sam68, an RNA-binding protein implicated in several aspects of RNA metabolism. Sam68 expression and localization within the cells is stage specific: it is expressed in the nucleus of spermatogonia, it disappears at the onset of meiosis (leptotene/zygotene stages), and it accumulates again in the nucleus of pachytene spermatocytes and round spermatids. During the meiotic divisions, Sam68 translocates to the cytoplasm where it is found associated with the polysomes. Translocation correlates with serine/threonine phosphorylation and it is blocked by inhibitors of the mitogen activated protein kinases ERK1/2 and of the maturation promoting factor cyclinB-cdc2 complex. Both kinases associate with Sam68 in pachytene spermatocytes and phosphorylate the regulatory regions upstream and downstream of the Sam68 RNA-binding motif. Molecular cloning of the mRNAs associated with Sam68 in mouse spermatocytes reveals a subset of genes that might be posttranscriptionally regulated by this RNA-binding protein during spermatogenesis. We also demonstrate that Sam68 shuttles between the nucleus and the cytoplasm in secondary spermatocytes, suggesting that it may promote translation of specific RNA targets during the meiotic divisions.

The online version of this article contains supplemental material at MBC Online (http://www.molbiolcell.org).

Address correspondence to: Claudio Sette (claudio.sette{at}uniroma2.it).

This article has been cited by other articles:

				R. Busa, R. Geremia, and C. Sette Genotoxic stress causes the accumulation of the splicing regulator Sam68 in nuclear foci of transcriptionally active chromatin Nucleic Acids Res., January 27, 2010; (2010): gkq004v1 - gkq004. [Abstract] [Full Text] [PDF]

				C. Sette, V. Messina, and M. P. Paronetto Sam68: A New STAR in the Male Fertility Firmament J Androl, January 1, 2010; 31(1): 66 - 74. [Abstract] [Full Text] [PDF]

				K. Ewen, M. Baker, D. Wilhelm, R. J. Aitken, and P. Koopman Global Survey of Protein Expression during Gonadal Sex Determination in Mice Mol. Cell. Proteomics, December 1, 2009; 8(12): 2624 - 2641. [Abstract] [Full Text] [PDF]

				M. P. Paronetto, V. Messina, E. Bianchi, M. Barchi, G. Vogel, C. Moretti, F. Palombi, M. Stefanini, R. Geremia, S. Richard, et al. Sam68 regulates translation of target mRNAs in male germ cells, necessary for mouse spermatogenesis J. Cell Biol., April 20, 2009; 185(2): 235 - 249. [Abstract] [Full Text] [PDF]

				M.-E. Huot, C. M. Brown, N. Lamarche-Vane, and S. Richard An Adaptor Role for Cytoplasmic Sam68 in Modulating Src Activity during Cell Polarization Mol. Cell. Biol., April 1, 2009; 29(7): 1933 - 1943. [Abstract] [Full Text] [PDF]

				A. Bianchini, M. Loiarro, P. Bielli, R. Busa, M. P. Paronetto, F. Loreni, R. Geremia, and C. Sette Phosphorylation of eIF4E by MNKs supports protein synthesis, cell cycle progression and proliferation in prostate cancer cells Carcinogenesis, December 1, 2008; 29(12): 2279 - 2288. [Abstract] [Full Text] [PDF]

				I. Ehrmann, C. Dalgliesh, A. Tsaousi, M. P. Paronetto, B. Heinrich, R. Kist, P. Cairns, W. Li, C. Mueller, M. Jackson, et al. Haploinsufficiency of the germ cell-specific nuclear RNA binding protein hnRNP G-T prevents functional spermatogenesis in the mouse Hum. Mol. Genet., September 15, 2008; 17(18): 2803 - 2818. [Abstract] [Full Text] [PDF]

				M. Smida, A. Posevitz-Fejfar, V. Horejsi, B. Schraven, and J. A. Lindquist A novel negative regulatory function of the phosphoprotein associated with glycosphingolipid-enriched microdomains: blocking Ras activation Blood, July 15, 2007; 110(2): 596 - 625. [Abstract] [Full Text] [PDF]

				M. P. Paronetto, T. Achsel, A. Massiello, C. E. Chalfant, and C. Sette The RNA-binding protein Sam68 modulates the alternative splicing of Bcl-x J. Cell Biol., March 26, 2007; 176(7): 929 - 939. [Abstract] [Full Text] [PDF]