testis-speciﬁc phosphoglycerate kinase (PGK-2) by monoclonal antibodies. EMBO J., 1, 479–484. 3. Robinson,M.O., McCarrey,J.R. and Simon,M.I. (1989) Transcriptional regulatory regions of testis-speciﬁc PGK2 deﬁned in transgenic mice. Proc. Natl Acad. Sci. USA., 86, 8437–8441. 4. Yoshioka,H., Geyer,C.B., Hornecker,J.L., Patel,K.T. and McCarrey,J.R. (2007) In vivo analysis of developmentally and evolutionarily dynamic protein-DNA interactions regulating transcription of the Pgk2 gene during mammalian spermatogenesis. Mol. Cell Biol., 27, 7871–7885. 5. Iguchi,N., Tobias,J.W. and Hecht,N.B. (2006) Expression proﬁling reveals meiotic male germ cell mRNAs that are translationally up- and down-regulated. Proc. Natl Acad. Sci. USA, 103, 7712–7717. 6. Braun,R.E. (1998) Post-transcriptional control of gene expression during spermatogenesis. Semin. Cell Dev. Biol., 9, 483–489. 7. Yang,J., Morales,C.R., Medvedev,S., Schultz,R.M. and Hecht,N.B. (2007) In the absence of the mouse DNA/RNA-binding protein MSY2, messenger RNA instability leads to spermatogenic arrest. Biol. Reprod., 76, 48–54. 8. Yang,J., Medvedev,S., Yu,J., Tang,L.C., Agno,J.E., Matzuk,M.M., Schultz,R.M. and Hecht,N.B. (2005) Absence of the DNA-/RNA- binding protein MSY2 results in male and female infertility. Proc. Natl Acad. Sci. USA, 102, 5755–5760. 9. Xu,M. and Hecht,N.B. (2007) Polypyrimidine tract binding protein 2 stabilizes phosphoglycerate kinase 2 mRNA in murine male germ cells by binding to its 3’UTR. Biol. Reprod., 76, 1025–1033. 10. Yang,J., Medvedev,S., Reddi,P.P., Schultz,R.M. and Hecht,N.B. (2005) The DNA/RNA-binding protein MSY2 marks speciﬁc transcripts for cytoplasmic storage in mouse male germ cells. Proc. Natl Acad. Sci. USA, 102, 1513–1518. 11. Markovtsov,V., Nikolic,J.M., Goldman,J.A., Turck,C.W., Chou,M.Y. and Black,D.L. (2000) Cooperative assembly of an hnRNP complex induced by a tissue-speciﬁc homolog of polypyrimidine tract binding protein. Mol. Cell Biol., 20, 7463–7479. 12. Tillmar,L., Carlsson,C. and Welsh,N. (2002) Control of insulin mRNA stability in rat pancreatic islets. Regulatory role of a 3’-untranslated region pyrimidine-rich sequence. J. Biol. Chem., 277, 1099–1106. 13. Knoch,K.P., Bergert,H., Borgonovo,B., Saeger,H.D., Altkruger,A., Verkade,P. and Solimena,M. (2004) Polypyrimidine tract-binding protein promotes insulin secretory granule biogenesis. Nat. Cell Biol., 6, 207–214. 14. Hamilton,B.J., Genin,A., Cron,R.Q. and Rigby,W.F. (2003) Delineation of a novel pathway that regulates CD154 (CD40 ligand) expression. Mol. Cell Biol., 23, 510–525. 15. Pautz,A., Linker,K., Hubrich,T., Korhonen,R., Altenhofer,S. and Kleinert,H. (2006) The polypyrimidine tract-binding protein (PTB) is involved in the post-transcriptional regulation of human inducible nitric oxide synthase expression. J. Biol. Chem., 281, 32294–32302. 16. Hellen,C.U., Witherell,G.W., Schmid,M., Shin,S.H., Pestova,T.V., Gil,A. and Wimmer,E. (1993) Cytoplasmic 57-kDa protein that is required for translation of picornavirus RNA by internal ribosomal entry is identical to the nuclear pyrimidine tract-binding protein. Proc. Natl Acad. Sci. USA, 90, 7642–7646. 17. Black,D.L. (2003) Mechanisms of alternative pre-messenger RNA splicing. Annu. Rev. Biochem., 72, 291–336. 18. Min,H., Turck,C.W., Nikolic,J.M. and Black,D.L. (1997) A new regulatory protein, KSRP, mediates exon inclusion through an intronic splicing enhancer. Genes Dev., 11, 1023–1036. 19. Gherzi,R., Lee,K.Y., Briata,P., Wegmuller,D., Moroni,C., Karin,M. and Chen,C.Y. (2004) A KH domain RNA binding protein, KSRP, promotes ARE-directed mRNA turnover by recruiting the degradation machinery. Mol. Cell, 14, 571–583. 20. Dean,J.L., Sully,G., Clark,A.R. and Saklatvala,J. (2004) The involvement of AU-rich element-binding proteins in p38 Nucleic Acids Research, 2008, Vol. 36, No. 22 7167 mitogen-activated protein kinase pathway-mediated mRNA stabilisation. Cell. Signal., 16, 1113–1121. 21. Linker,K., Pautz,A., Fechir,M., Hubrich,T., Greeve,J. and Kleinert,H. (2005) Involvement of KSRP in the post-transcriptional regulation of human iNOS expression-complex interplay of KSRP with TTP and HuR. Nucleic Acids Res., 33, 4813–4827. 22. Briata,P., Forcales,S.V., Ponassi,M., Corte,G., Chen,C.Y., Karin,M., Puri,P.L. and Gherzi,R. (2005) p38-dependent phosphorylation of the mRNA decay-promoting factor KSRP controls the stability of select myogenic transcripts. Mol. Cell, 20, 891–903. 23. Gherzi,R., Trabucchi,M., Ponassi,M., Ruggiero,T., Corte,G., Moroni,C., Chen,C.Y., Khabar,K.S., Andersen,J.S. and Briata,P. (2006) The RNA-binding protein KSRP promotes decay of beta-catenin mRNA and is inactivated by PI3K-AKT signaling. PLoS Biol., 5, e5. 24. Chou,C.F., Mulky,A., Maitra,S., Lin,W.J., Gherzi,R., Kappes,J. and Chen,C.Y. (2006) Tethering KSRP, a decay-promoting AU-rich element-binding protein, to mRNAs elicits mRNA decay. Mol. Cell Biol., 26, 3695–3706. 25. Nechama,M., Ben-Dov,I.Z., Briata,P., Gherzi,R. and Naveh- Many,T. (2008) The mRNA decay promoting factor K-homology splicing regulator protein post- transcriptionally determines parathyroid hormone mRNA levels. FASEB J., 22, 3458–3468. 26. Winzen,R., Thakur,B.K., Dittrich-Breiholz,O., Shah,M., Redich,N., Dhamija,S., Kracht,M. and Holtmann,H. (2007) Functional analysis of KSRP interaction with the AU-rich element of interleukin-8 and identiﬁcation of inﬂammatory mRNA targets. Mol. Cell Biol., 27, 8388–8400. 27. Hall,M.P., Huang,S. and Black,D.L. (2004) Diﬀerentiation-induced colocalization of the KH-type splicing regulatory protein with polypyrimidine tract binding protein and the c-src pre-mRNA. Mol. Biol. Cell, 15, 774–786. 28. McCarrey,J.R., Berg,W.M., Paragioudakis,S.J., Zhang,P.L., Dilworth,D.D., Arnold,B.L. and Rossi,J.J. (1992) Diﬀerential transcription of Pgk genes during spermatogenesis in the mouse. Dev. Biol., 154, 160–168. 29. Kumari,M., Stroud,J.C., Anji,A. and McCarrey,J.R. (1996) Diﬀerential appearance of DNase I-hypersensitive sites correlates with diﬀerential transcription of Pgk genes during spermatogenesis in the mouse. J. Biol. Chem., 271, 14390–14397. 30. Gu,W., Pan,F., Zhang,H., Bassell,G.J. and Singer,R.H. (2002) A predominantly nuclear protein aﬀecting cytoplasmic localization of beta-actin mRNA in ﬁbroblasts and neurons. J. Cell Biol., 156, 41–51. 31. Pan,F., Hu¨ ttelmaier,S., Singer,R.H. and Gu,W. (2007) ZBP2 facilitates binding of ZBP1 to beta-actin mRNA during transcription. Mol. Cell Biol., 27, 8340–8351. 32. Chen,C.Y. and Shyu,A.B. (1995) AU-rich elements: characterization and importance in mRNA degradation. Trends Biochem. Sci., 20, 465–470. 33. Seok,H., Cho,J., Cheon,M. and Park,I.S. (2002) Biochemical characterization of apoptotic cleavage of KH-type splicing regulatory protein (KSRP)/far upstream element-binding protein 2 (FBP2). Protein Pept. Lett., 9, 511–519. 34. Garcı´ a-Mayoral,M.F., Dı´ az-Moreno,I., Hollingworth,D. and Ramos, A. (2008) The sequence selectivity of KSRP explains its ﬂexibility in the recognition of the RNA targets. Nucleic Acids Res., 36, 5290–5296. 35. Siomi,H., Matunis,M.J., Michael,W.M. and Dreyfuss,G. (1993) The pre-mRNA binding K protein contains a novel evolutionarily conserved motif. Nucleic Acids Res., 21, 1193–1198. 36. Cho,Y.S., Chennathukuzhi,V.M., Handel,M.A., Eppig,J. and Hecht,N.B. (2004) The relative levels of translin-associated factor X (TRAX) and testis brain RNA-binding protein determine their nucleocytoplasmic distribution in male germ cells. J. Biol. Chem., 279, 31514–31523. 37. Kroll,T.T., Zhao,W.M., Jiang,C. and Huber,P.W. (2002) A homolog of FBP2/KSRP binds to localized mRNAs in Xenopus oocytes. Development, 129, 5609–5619.