The binding activity of yeast RNAs to yeast Hek2p and mammalian hnRNP K proteins, determined using the three-hybrid system.
K homology (KH) domains are scaffolds for the binding of RNAs by the heterogeneous nuclear ribonucleoprotein (hnRNP) K protein and its yeast ortholog, Hek2p. KH domains are remarkably conserved between mammals and yeast. To assess the binding activity for yeast RNA of the two proteins, we used full-length K protein and Hek2p as baits in the yeast three-hybrid system. All the unique RNA sequences bound by Hek2p and all but two bound by K protein represented different fragments of only two transcripts, encoded by the 18S and 25S ribosomal RNA genes. Most of them were transcribed from the antisense strand. The RNA-binding activity of K protein was significantly higher than that of Hek2p. These results and those from our previously published reports demonstrate that the specificity of target RNA recognition by both the K protein and Hek2p depends on both RNA-specific sequences and the structure of the protein. Both mammalian K protein and its yeast ortholog may be involved in the regulation of gene expression.
Paziewska
Agnieszka
A
Department of Gastroenterology, Medical Center for Postgraduate Education at Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Roentgena 5, 02-781 Warsaw, Poland.
Wyrwicz
Lucjan S
LS
Ostrowski
Jerzy
J
D000818:Animals; D017930:Genes, Reporter; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
C443676:HEK2 protein, S cerevisiae; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012331:RNA, Fungal; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins