| First Author | Monarez RR | Year | 2007 |
| Journal | Biochem J | Volume | 401 |
| Issue | 3 | Pages | 651-8 |
| PubMed ID | 17029590 | Mgi Jnum | J:118578 |
| Mgi Id | MGI:3699791 | Doi | 10.1042/BJ20061097 |
| Citation | Monarez RR, et al. (2007) Polyadenylation proteins CstF-64 and tauCstF-64 exhibit differential binding affinities for RNA polymers. Biochem J 401(3):651-8 |
| abstractText | CstF-64 (cleavage stimulation factor-64), a major regulatory protein of polyadenylation, is absent during male meiosis. Therefore a paralogous variant, tauCstF-64 is expressed in male germ cells to maintain normal spermatogenesis. Based on sequence differences between tauCstF-64 and CstF-64, and on the high incidence of alternative polyadenylation in testes, we hypothesized that the RBDs (RNA-binding domains) of tauCstF-64 and CstF-64 have different affinities for RNA elements. We quantified K(d) values of CstF-64 and tauCstF-64 RBDs for various ribopolymers using an RNA cross-linking assay. The two RBDs had similar affinities for poly(G)18, poly(A)18 or poly(C)18, with affinity for poly(C)18 being the lowest. However, CstF-64 had a higher affinity for poly(U)18 than tauCstF-64, whereas it had a lower affinity for poly(GU)9. Changing Pro-41 to a serine residue in the CstF-64 RBD did not affect its affinity for poly(U)18, but changes in amino acids downstream of the C-terminal alpha-helical region decreased affinity towards poly(U)18. Thus we show that the two CstF-64 paralogues differ in their affinities for specific RNA sequences, and that the region C-terminal to the RBD is mportant in RNA sequence recognition. This supports the hypothesis that tauCstF-64 promotes germ-cell-specific patterns of polyadenylation by binding to different downstream sequence elements. |
