Pre-messenger RNA cleavage factor I (CFIm): potential role in alternative polyadenylation during spermatogenesis.
A hallmark of male germ cell gene expression is the generation by alternative polyadenylation of cell-specific mRNAs, many of which utilize noncanonical A(A/U)UAAA-independent polyadenylation signals. Cleavage factor I (CFIm), a component of the pre-mRNA cleavage and polyadenylation protein complex, can direct A(A/U)UAAA-independent polyadenylation site selection of somatic cell mRNAs. Here we report that the CFIm subunits NUDT21/CPSF5 and CPSF6 are highly enriched in mouse male germ cells relative to somatic cells. Both subunits are expressed from spermatogenic cell mRNAs that are shorter than the corresponding somatic transcripts. Complementary DNA sequencing and Northern blotting revealed that the shorter Nudt21 and Cpsf6 mRNAs are generated by alternative polyadenylation in male germ cells using proximal poly(A) signals. Both sets of transcripts contain CFIm binding sites within their 3'-untranslated regions, suggesting autoregulation of CFIm subunit formation in male germ cells. CFIm subunit mRNA and protein levels exhibit distinct developmental variation during spermatogenesis, indicating stage-dependent translational and/or posttranslational regulation. CFIm binding sites were identified near the 3' ends of numerous male germ cell transcripts utilizing A(A/U)UAAA-independent sites. Together these findings suggest that CFIm complexes participate in alternative polyadenylation directed by noncanonical poly(A) signals during spermatogenesis.
Sartini
Becky L
BL
Department of Molecular and Cellular Physiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Wang
Hang
H
Wang
Wei
W
Millette
Clarke F
CF
Kilpatrick
Daniel L
DL
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D039223:Cleavage And Polyadenylation Specificity Factor / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D026723:Polyadenylation / Q000235:genetics*; D021122:Protein Subunits / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D022821:RNA Splice Sites; D017386:Sequence Homology, Amino Acid; D013091:Spermatogenesis / Q000235:genetics*; D013093:Spermatogonia / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics / Q000502:physiology*
C529056:CPSF6 protein, mouse; D039223:Cleavage And Polyadenylation Specificity Factor; C529055:Nudt21 protein, mouse; D021122:Protein Subunits; D012322:RNA Precursors; D022821:RNA Splice Sites; D039221:mRNA Cleavage and Polyadenylation Factors