A finger protein structurally similar to TFIIIA that binds exclusively to 5S RNA in Xenopus

The stem-loop binding protein (SLBP) is the posttranscriptional regulator of histone mRNA in metazoan cells. SLBP binds histone pre-mRNAs and facilitates 3-end processing by promoting stable association of U7 snRNP with the pre-mRNA. To identify other factors involved in histone pre-mRNA processing, we used a modified yeast two-hybrid assay in which SLBP and its RNA target were coexpressed as bait. A novel zinc finger protein, hZFP100, which interacts with the SLBP/RNA complex but not with free SLBP, was cloned. The interaction requires regions of SLBP that are important for histone pre-mRNA processing. Antibodies to hZFP100 precipitate U7 snRNA, and expression of hZFP100 in Xenopus oocytes stimulates processing of histone pre-mRNA, showing that hZFP100 is a component of the processing machinery.

Section: The Rna-supplemented Two-hybrid System Can Be Used To Clone mentioning

confidence: 99%

A novel zinc finger protein is associated with U7 snRNP and interacts with the stem–loop binding protein in the histone pre-mRNP to stimulate 3′-end processing

Domiński¹,

Erkmann²,

Yang³

et al. 2002

“…Drosophila nuclear extract was digested with increasing amounts of trypsin, and identical samples were fractionated by electrophoresis in an SDS-polyacrylamide gel; the polypeptides were transferred to nitrocellulose and probed with either TBS (not shown), mAb Y1D2, or mAb Y2A11. and in some RNA-binding proteins (Miller et al 1985;Joho et al 1990). The PEP fingers are distinctive in possessing five amino acid residues between the histidine residues rather than four (Fig.…”

Section: The Pep Antigen Contains Numerous Motifs Suggesting Nucleic mentioning

confidence: 99%

A unique zinc finger protein is associated preferentially with active ecdysone-responsive loci in Drosophila.

Amero¹,

Elgin²,

Beyer³

1991

Using an immunochemical approach, we have identified a unique antigen, PEP (protein on ecdysone puffs), which is associated in third-instar larvae with the active ecdysone-regulated loci on polytene chromosomes; PEP is not associated with most intermolt puffs and is found on some, but not all, heat shock-induced puffs. The distribution pattern changes with changing puffing patterns in the developmental program. We have screened an expression library and recovered a cDNA clone encoding PEP. PEP possesses multiple potential nucleic acid-and protein-binding regions: a glycine-and asparagine-rich amino terminus, four zinc finger motifs, two very acidic segments, two short basic stretches, and an alanine-and proline-rich carboxyl terminus. The Pep gene maps by in situ hybridization to the cytological locus 74F, adjacent to the early ecdysone-responsive region; however, the gene is not regulated by ecdysone at the level of transcription. The pattern of Pep expression through development suggests that maternal Pep gene transcripts are supplied to the embryo, and that the abundance of Pep gene transcripts decreases to a lower, fairly constant level thereafter. This unusual protein may play a role in the process of gene activation, or possibly in RNA processing, for a defined set of developmentally regulated loci.

“…Barrett and Sommerville (1987) claimed that both proteins in the 42S RNP storage particle of oocytes bind and footprint 5S RNA genes. We have shown that this is attributable to TFIIIA contamination of 42S RNP preparations (Joho et al 1990). One of the two proteins in the 42S particle that we refer to as p43 binds specifically to 5S RNA but not to 5S DNA.…”

Section: Function Of S-tfiiiamentioning

confidence: 99%

“…One of the two proteins in the 42S particle that we refer to as p43 binds specifically to 5S RNA but not to 5S DNA. It is different but related to TFIIIA and only found in oocytes (Joho et al 1990). Recently, Blanco et al (1989) described a 42-kD protein present in oocytes and somatic cells that they believe functions as a specific transcription factor for somatic 5S RNA genes.…”

Section: Function Of S-tfiiiamentioning

confidence: 99%

The characterization of the TFIIIA synthesized in somatic cells of Xenopus laevis.

Kim

Darby²,

Joho³

et al. 1990

In somatic cells of Xenopus, transcription of the TFIIIA gene initiates >200 bp upstream from the start site used in oocytes. The resultant mRNA encodes a protein, S-TFIIIA, that is 22 amino acids longer at its amino terminus than the abundant form of TFIIIA in oocytes (O-TFIIIA). S-TFIIIA binds the 5S RNA gene and 5S RNA, and both O-and S-TFIIIA promote the formation of stable transcription complexes on oocyte-type 5S RNA genes in an oocyte nuclear extract. We have not found any functional difference between the two forms of TFIIIA. Different transcription start sites suggest differential promoter usagemone in oocytes that permits high levels of gene activity and another that is used in somatic cells for low-level TFIIIA mRNA synthesis.[Key Words: Xenopus; TFIIIA; zinc finger protein; transcription]Received March 3, 1990; revised version accepted June 27, 1990.The 38-kD zinc finger protein TFIIIA is synthesized at high rates and stored in large amounts in Xenopus oocytes (Engelke et al. 1980). There are two oocyte-specific functions carried out by this protein (O-TFIIIA). The first of these functions is the activation throughout oogenesis of a large multigene family encoding oocyte-specific 5S RNA genes. These 5S RNA genes are transcribed actively during oogenesis and then repressed in somatic cells where a much smaller multigene family, called somatic 5S RNA genes, encodes the 5S RNA synthesized for ribosomes (for review, see Wolffe and Brown 1988). The second function is the interaction of O-TFIIIA with 5S RNA forming a 7S RNP storage particle that accumulates in early oogenesis (Honda and Roeder 1988;Pelham and Brown 1980