Alternative splicing of pre-mRNAs of Arabidopsis serine/arginine-rich proteins: regulation by hormones and stresses

• Published in: The Plant journal : for cell and molecular biology Vol. 49; no. 6; pp. 1091 - 1107
• Main Authors: Palusa, Saiprasad Goud, Ali, Gul Shad, Reddy, Anireddy S.N
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-03-2007; Blackwell Publishing Ltd; Blackwell Science
• Subjects: alternative splicing; Alternative Splicing - drug effects; Alternative Splicing - physiology; Arabidopsis; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arginine - chemistry; Biological and medical sciences; Botany; Fundamental and applied biological sciences. Psychology; Genetics; Hormones; Molecular and cellular biology; Molecular biology; Molecular genetics; Nuclear Proteins - genetics; Plant Growth Regulators - pharmacology; Pre-mRNA splicing; Proteins; Ribonucleic acid; RNA; RNA Precursors - metabolism; RNA-Binding Proteins - genetics; Serine - chemistry; Serine-Arginine Splicing Factors; SR proteins; Stress; stresses; Transcription. Transcription factor. Splicing. Rna processing; Alternative splicing; Temperature; Cold; Arabidopsis; hormones; stresses; Stress; SR proteins; Gene; Cruciferae; Dicotyledones; Angiospermae; Spermatophyta; Pre-mRNA splicing
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/j.1365-313X.2006.03020.x

Precursor mRNAs with introns can undergo alternative splicing (AS) to produce structurally and functionally different proteins from the same gene. Here, we show that the pre-mRNAs of Arabidopsis genes that encode serine/arginine-rich (SR) proteins, a conserved family of splicing regulators in eukaryotes, are extensively alternatively spliced. Remarkably about 95 transcripts are produced from only 15 genes, thereby increasing the complexity of the SR gene family transcriptome by six-fold. The AS of some SR genes is controlled in a developmental and tissue-specific manner. Interestingly, among the various hormones and abiotic stresses tested, temperature stress (cold and heat) dramatically altered the AS of pre-mRNAs of several SR genes, whereas hormones altered the splicing of only three SR genes. These results indicate that abiotic stresses regulate the AS of the pre-mRNAs of SR genes to produce different isoforms of SR proteins that are likely to have altered function(s) in pre-mRNA splicing. Sequence analysis of splice variants revealed that predicted proteins from a majority of these variants either lack one or more modular domains or contain truncated domains. Because of the modular nature of the various domains in SR proteins, the proteins produced from splice variants are likely to have distinct functions. Together our results indicate that Arabidopsis SR genes generate surprisingly large transcriptome complexity, which is altered by stresses and hormones.