Expression and Functional Significance of Mouse Paraspeckle Protein 1 on Spermatogenesis

• Published in: Biology of reproduction Vol. 71; no. 3; pp. 926 - 932
• Main Authors: MYOJIN, Reiko, KUWAHARA, Sho, YASAKI, Tomohiko, MATSUNAGA, Takahito, SAKURAI, Takayuki, KIMURA, Minoru, UESUGI, Seiichi, KURIHARA, Yasuyuki
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01.09.2004
• Subjects: Animals; Biological and medical sciences; Chromatin - physiology; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; Male; Mammalian male genital system; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Morphology. Physiology; NIH 3T3 Cells; Nuclear Matrix - metabolism; Nuclear Matrix-Associated Proteins - metabolism; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Octamer Transcription Factors; PTB-Associated Splicing Factor; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Spermatogenesis - physiology; Transcriptional Activation - physiology; Vertebrates: reproduction; Vertebrata; Reproduction; Mammalia; Mouse; Spermatogenesis; Animal; Rodentia; Protein
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod.104.028159

Paraspeckle protein 1 (PSP1) in humans is a recently identified component protein of a novel nuclear body, paraspeckle. The protein has a DBHS ( D rosophila b ehavior, h uman s plicing) motif that is found in PSF and p54 nrb /NonO proteins. These DBHS-containing proteins have been reported to be involved in various nuclear events such as DNA replication, transcription, and mRNA processing. Here we show that mouse paraspeckle protein 1 (mPSP1; encoded by the Pspc1 gene) has two isoforms with different C-termini lengths. Abundant expression of the longer isoform (mPSP1-α) and the shorter one (mPSP1-β) were observed in testis and kidney, respectively. Transiently expressed mPSP1-α was localized in nuclei, but mPSP1-β was localized in both nuclei and cytoplasm. These observations suggest that alternative splicing regulates tissue distribution and subcellular localization. Like other DBHS-containing proteins, mPSP1 has RNA-binding activity. In mouse testis, mPSP1-α was found in the nuclear matrix fraction. Furthermore, by coimmunoprecipitation, we confirmed that mPSP1 interacts with other DBHS-containing proteins, PSF and p54 nrb /NonO. Therefore, we conclude that mPSP1 may regulate multiple phases of important nuclear events during spermatogenesis.