%0 Journal Article
%T Alternative trans-splicing of Caenorhabditis elegans sma-9/schnurri generates a short transcript that provides tissue-specific function in BMP signaling
%A Jianghua Yin
%A Ling Yu
%A Cathy Savage-Dunn
%J BMC Molecular Biology
%D 2010
%I BioMed Central
%R 10.1186/1471-2199-11-46
%X We demonstrate here that the shorter transcripts are expressed in vivo. Furthermore, we find that one of the short transcripts plays a tissue-specific role in sma-9 function, contributing to the patterning of male-specific sensory rays, but not to the regulation of body size. Based on previous results, we suggest that this transcript encodes a C-terminal SMA-9 isoform that may provide transcriptional activation activity, while full length isoforms may mediate transcriptional repression and/or activation in a context-dependent manner.The alternative trans-splicing of sma-9 may contribute to the diversity of functions necessary to mediate tissue-specific outputs of BMP signaling.The transforming growth factor ¦Â (TGF¦Â) superfamily comprises a large number of secreted peptide growth factors that have major regulatory effects on cell growth and differentiation [1,2]. Members of this superfamily include the TGF¦Âs, the prototypes of the superfamily; the bone morphogenetic proteins (BMPs); and other members such as activin, inhibin, and Nodal. TGF¦Â superfamily ligands bind to a heteromeric receptor complex at the cell surface. This complex contains two related transmembrane serine/threonine kinases, the type I and type II receptors [3,4]. Signaling downstream of the receptors is mediated by the Smad proteins, which shuttle between the cytoplasm and nucleus to regulate target gene expression [5]. Type I receptors directly activate receptor-regulated Smads (R-Smads) by phosphorylation at C-terminal SXS sequences [6,7]. Phosphorylation of R-Smads promotes heterotrimeric complex formation with Co-Smads and accumulation in the nucleus to regulate gene transcription [7-11]. In mammals, five R-Smads are present: two (Smad2,3) that transduce TGF¦Â/activin/Nodal signals and three (Smad1,5,8) that transduce BMP signals. Strikingly, the TGF¦Â family ligands far outnumber the Smads available for signal transduction. Furthermore, many of these ligands are capable of eliciting diverse cont
%U http://www.biomedcentral.com/1471-2199/11/46