Expression and functional significance of mouse paraspeckle protein 1 on spermatogenesis.
Paraspeckle protein 1 (PSP1) in humans is a recently identified component protein of a novel nuclear body, paraspeckle. The protein has a DBHS (Drosophila behavior, human splicing) 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-alpha) and the shorter one (mPSP1-beta) were observed in testis and kidney, respectively. Transiently expressed mPSP1-alpha was localized in nuclei, but mPSP1-beta 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-alpha 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.
Myojin
Reiko
R
Department of Chemistry and Bioengineering, Graduate School of Engineering, Yokohama National University, Yokohama 240-0851, Japan.
Kuwahara
Sho
S
Yasaki
Tomohiko
T
Matsunaga
Takahito
T
Sakurai
Takayuki
T
Kimura
Minoru
M
Uesugi
Seiichi
S
Kurihara
Yasuyuki
Y
D000818:Animals; D002843:Chromatin / Q000502:physiology; D004268:DNA-Binding Proteins; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D015530:Nuclear Matrix / Q000378:metabolism; D034521:Nuclear Matrix-Associated Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D050810:Octamer Transcription Factors; D000072670:PTB-Associated Splicing Factor; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D013091:Spermatogenesis / Q000502:physiology*; D015533:Transcriptional Activation / Q000502:physiology
D002843:Chromatin; D004268:DNA-Binding Proteins; C083214:NONO protein, human; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D050810:Octamer Transcription Factors; C450059:PSPC1 protein, human; D000072670:PTB-Associated Splicing Factor; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C494389:paraspeckle protein 1, mouse