Nucleic Acids Research, Vol 25, Issue 23 4808-4815, Copyright © 1997 by Oxford University Press
DB Zerby and JR Patton
Small nuclear RNAs (snRNA), cofactors in the splicing of pre-mRNA, are
highly modified. In this report the modification of human U4 RNA was
studied using cell extracts and in vitro synthesized, and therefore
unmodified, U4 RNA. The formation of pseudouridine (Psi) at positions 4, 72
and 79 in U4 RNA was dependent on an RNA-containing cofactor, since the
activities in the extracts were micrococcal nuclease (MN) sensitive.
Extracts were fractionated on glycerol gradients and there was a broad peak
of reconstitution activity centered at 14 S. Reconstitution was not due to
additional enzymatic activity, since the peak fraction was MN sensitive.
Oligodeoxynucleotide-mediated RNase H digestion of U6 RNA in the extracts
inhibited formation of Psi in U4 RNA. From glycerol gradient analysis we
determined that exogenously added U4 RNA that is associated with U6 RNA
(sedimentation velocity 16 S) was significantly higher in Psi content than
U4 RNA not associated with U6 RNA (8 S). Competitive inhibitors of Psi
synthases, 5- fluorouridine-containing (5-FU) wild-type and mutant U4 RNAs,
were used to investigate formation of Psi in U4 RNA. Deletions and point
mutations in these 5-FU-containing U4 RNAs affected their ability to
inhibit Psi synthase in vitro. With the aid of these potent inhibitors it
was determined that at least two separate activities modify the uridines at
these positions.
ARTICLES
Modification of human U4 RNA requires U6 RNA and multiple pseudouridine synthases
Department of Pathology, School of Medicine, University of South Carolina, Columbia, SC 29208, USA.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  H. Zhou, Y.-Q. Chen, Y.-P. Du, and L.-H. Qu The Schizosaccharomyces pombe mgU6-47 gene is required for 2'-O-methylation of U6 snRNA at A41 Nucleic Acids Res., February 15, 2002; 30(4): 894 - 902. [Abstract] [Full Text] [PDF]
|
|