Previous Article | Next Article ![]()
Mol. Cell. Biol., Apr 1997, 2291-2300, Vol 17, No. 4
MV Murray, MA Turnage, KJ Williamson, WR Steinhauer and LL Searles
Mutations of the Drosophila melanogaster suppressor of sable [su(s)] gene,
which encodes a 150-kDa nuclear protein [Su(s)], increase the accumulation
of specific transcripts in a manner that is not well understood but that
appears to involve pre-mRNA processing. Here, we report biochemical
analysis of purified, recombinant Su(s) [rSu(s)] expressed in baculovirus
and in Escherichia coli as maltose binding protein (MBP) fusions and
immunocytochemical analysis of endogenous Su(s). This work has shown that
purified, baculovirus-expressed rSu(s) binds to RNA in vitro with a high
affinity and limited specificity. Systematic evolution of ligands by
exponential enrichment was used to identify preferred RNA targets of
rSu(s), and a large proportion of RNAs isolated contain a full or partial
match to the consensus sequence UCAGUAGUCU, which was confirmed to be a
high-affinity rSu(s) binding site. An MBP-Su(s) fusion protein containing
the N-terminal third of Su(s) binds RNAs containing this sequence with a
higher specificity than full-length, baculovirus-expressed rSu(s). The
consensus sequence resembles both a cryptic 5' splice site and a sequence
that is found near the 5' end of some Drosophila transcripts.
Immunolocalization studies showed that endogenous Su(s) is distributed in a
reticulated pattern in Drosophila embryo and salivary gland nuclei. In
salivary gland cells, Su(s) is found both in the nucleoplasm and in
association with a subset of polytene chromosome bands. Considering these
and previous results, we propose two models to explain how su(s) mutations
affect nuclear pre-mRNA processing.
Copyright © 1997, American Society for Microbiology
The Drosophila suppressor of sable protein binds to RNA and associates with a subset of polytene chromosome bands
Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill 27599, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»