QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Blanco, J Articles by Gottesfeld, J Search for Related Content PubMed PubMed Citation Articles by Blanco, J Articles by Gottesfeld, J Social Bookmarking                   What's this?

Research Papers

Two TFIIIA activities regulate expression of the Xenopus 5S RNA gene families.

Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, California 92037.

Abstract

Immunoblotting experiments with polyclonal and monoclonal anti-transcription factor IIIA (TFIIIA) antibodies reveal different electrophoretic forms of TFIIIA in extracts from immature and mature oocytes of Xenopus laevis. The well-characterized 39-kD TFIIIA species is present in approximately 10(12) copies per cell in stage I-III previtellogenic oocytes and declines in abundance by 10- to 20-fold during oogenesis. An immunologically related protein of apparent molecular mass of 42 kD is present at 2-4% of the level of 39-kD TFIIIA in immature oocytes, and the level of this protein increases dramatically during oogenesis. Both the 39- and 42-kD proteins are complexed with 5S RNA in 7S ribonucleoprotein (RNP) particles. High-level transcription of the oocyte-type 5S genes in vitro requires 39-kD immature oocyte TFIIIA, whereas both 39-kD TFIIIA and the mature oocyte TFIIIA species of 42 kD support somatic-type 5S transcription. TFIIIA of 42 kD does not support oocyte-type 5S transcription in a fractionated transcription system derived from mature oocytes. Both proteins, however, bind the oocyte-type and somatic-type genes with comparable affinities and exhibit similar DNase footprints on both genes. These results suggest a model for the developmental regulation of 5S RNA gene transcription where 42-kD TFIIIA serves as an activator of somatic-type 5S transcription and as a repressor of oocyte-type transcription during early embryogenesis.

CiteULike

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				A. Wolffe The role of transcription factors, chromatin structure and DNA replication in 5 S RNA gene regulation J. Cell Sci., January 8, 1994; 107(8): 2055 - 2063. [Abstract] [PDF]

				D D Brown Is there a Xenopus transcription factor that can substitute for TFIIIA? Re: Two TFIIIA activities regulate expression of the Xenopus 5S RNA gene families. Genes & Dev., October 1, 1991; 5(10): 1737 - 1738. [PDF]

				S H Kim, M K Darby, K E Joho, and D D Brown The characterization of the TFIIIA synthesized in somatic cells of Xenopus laevis. Genes & Dev., September 1, 1990; 4(9): 1602 - 1610. [Abstract] [PDF]