Translational recruitment of Xenopus maternal mRNAs in response to poly(A) elongation requires initiation factor eIF4G-1.

摘要: Abstract Xenopusoocytes accumulate maternal mRNAs which are then recruited to ribosomes during meiotic cell cycle progression in response progesterone and coincident with poly(A) elongation. Prior stimulation, most protein synthesis (∼70%) does not require intact translation factor eIF4G (B. D. Keiper R. E. Rhoads, 1997,Nucleic Acids Res.25, 395–402). In the present study we have addressed requirement of recruitment meiosis. Cleavage by coxsackievirus protease 2A inhibited progesterone-induced 88% oocytes; prevented encoding cyclin B1, c-Mos, D7, B9; disrupted association poly(A)-binding protein. Poly(A) elongation, however, was cleavage. Injection MPF restored >60% oocytes but B1 or B9 mRNA. Previously were removed from polyribosomes following subsequent cleavage eIF4G, indicating that is required both recruit also maintain on polyribosomes. The expression a cleavage-resistant variant human eIF4G-1 (G486E) significantly ability synthesize c-Mos translate exogenous β-globin mRNA, inhibition due alone. These results indicate for poly(A)-dependent several (cyclin B9) proteins.