In vitro assembly of yeast 5S rRNA and a fusion protein containing ribosomal protein L5 and maltose binding protein

Ribosomal protein L5 binds specifically to 5S rRNA to form a complex that is a precursor to 60S subunit assembly in vivo. Analyses in yeast cells, mammalian cells, and Xenopus embryos have shown that the accumulation of L5 is not coordinated with the expression of other ribosomal proteins. In this study, the primary structure and developmental expression of Xenopus ribosomal protein L5 were examined to determine the basis for its distinct regulation. These analyses showed that L5 expression could either coincide with 5S rRNA synthesis and ribosome assembly or be controlled independently of these events at different stages of Xenopus development. L5 synthesis during oogenesis was uncoupled from the accumulation of 5S rRNa but coincided with subunit assembly. In early embryos, the inefficient translation of L5 mRNA resulted in the accumulation of a stable L5-5S rRNA complex before ribosome assembly at later stages of development. Additional results demonstrated that L5 protein synthesized in vitro bound specifically to 5S rRNA.

Download Full-text

Developmental expression and 5S rRNA-binding activity of Xenopus laevis ribosomal protein L5.

Molecular and Cellular Biology ◽

10.1128/mcb.9.12.5281 ◽

1989 ◽

Vol 9 (12) ◽

pp. 5281-5288 ◽

Cited By ~ 35

Author(s):

W M Wormington

Keyword(s):

Ribosomal Protein ◽

Mammalian Cells ◽

Ribosomal Proteins ◽

5S Rrna ◽

Yeast Cells ◽

Developmental Expression ◽

Rrna Synthesis ◽

Ribosome Assembly ◽

Subunit Assembly ◽

Ribosomal Protein L5

Ribosomal protein L5 binds specifically to 5S rRNA to form a complex that is a precursor to 60S subunit assembly in vivo. Analyses in yeast cells, mammalian cells, and Xenopus embryos have shown that the accumulation of L5 is not coordinated with the expression of other ribosomal proteins. In this study, the primary structure and developmental expression of Xenopus ribosomal protein L5 were examined to determine the basis for its distinct regulation. These analyses showed that L5 expression could either coincide with 5S rRNA synthesis and ribosome assembly or be controlled independently of these events at different stages of Xenopus development. L5 synthesis during oogenesis was uncoupled from the accumulation of 5S rRNa but coincided with subunit assembly. In early embryos, the inefficient translation of L5 mRNA resulted in the accumulation of a stable L5-5S rRNA complex before ribosome assembly at later stages of development. Additional results demonstrated that L5 protein synthesized in vitro bound specifically to 5S rRNA.

Download Full-text

Effect of immunization of hamsters against recombinant P26h on fertility rates

Reproduction ◽

10.1530/rep.0.1230307 ◽

2002 ◽

pp. 307-313 ◽

Cited By ~ 18

Author(s):

C Gaudreault ◽

L Montfort ◽

R Sullivan

Keyword(s):

Zona Pellucida ◽

Binding Protein ◽

Maltose Binding Protein ◽

Fertilization Rate ◽

Active Immunization ◽

Antigenic Determinants ◽

Binding Assays ◽

Contraceptive Vaccine

Despite the various contraceptive methods available, an effective and inexpensive method remains to be established. Immunocontraception may help to achieve this goal. P26h has been proposed as a candidate for the development of a male contraceptive vaccine. P26h, a hamster sperm protein, interacts with the zona pellucida. Furthermore, in vivo fertilization can be blocked completely by active immunization of male hamsters against P26h. Maltose binding protein (MBP)-P26 shares antigenic determinants with the native P26h present on cauda epididymal spermatozoa. The aim of the present study was to reproduce the immunocontraceptive properties of native P26h by immunizing male hamsters against a recombinant P26h fused with a maltose binding protein (MBP). Active immunization of male hamsters with the MBP-P26h showed that specific anti-P26h circulating IgGs could be generated. Mating of immunized male hamsters with superovulated females resulted in a significant decrease, 20-25%, in the fertilization rate. This result is in agreement with results from in vitro sperm-zona pellucida binding assays. Indeed, the anti-recombinant P26h IgGs showed lower inhibitory properties when compared with anti-native P26h IgG. Despite the high anti-P26h IgG titres generated in hamsters, histological studies showed that active immunization has no pathological sequelae to the reproductive tissues. The potential of P26h as a candidate for a contraceptive vaccine is discussed.

Download Full-text