title: Differential expression of alternatively spliced mRNAs of Arabidopsis SR protein homologs, atSR30 and atSR45a, in response to environmental stress.
abstract: Serine/arginine-rich (SR) proteins are associated with either the regulation or the execution of both constitutive splicing and the selection of alternative splice sites in animals and plants. We demonstrated the molecular characterization of a homolog of SR protein, atSR45a, in Arabidopsis plants. Six types of mRNA variants (atSR45a-1a-e and atSR45a-2) were generated by the alternative selection of transcriptional initiation sites and the alternative splicing of introns in atSR45a pre-mRNA. The atSR45a-1a and -2 proteins, presumed mature forms, were located in the nucleus and interacted with U1-70K, suggesting that these proteins function as a splicing factor in Arabidopsis. The levels of the transcripts atSR45a and atSR30, SF2/ASF-like SR proteins, were increased by various types of stress, such as high-light irradiation and salinity. Furthermore, the splicing patterns of atSR45a and atSR30 pre-mRNA themselves were altered under these stressful conditions. In particular, the expression of atSR45a-1a, atSR45a-2, atSR30 mRNA1 and atSR30 mRNA3 was greatly increased by high-light irradiation. These results indicate that the regulation of transcription and alternative splicing of atSR45a and atSR30 is responsive to various stressful conditions.
authors.affiliation: Advanced Bioscience, Graduate School, Kinki University, 3327-204 Nakamachi, Nara, 631-8505 Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Tanabe
authors.forename: Kazuya
authors.initials: K
authors.lastname: Yoshimura
authors.forename: Ayako
authors.initials: A
authors.lastname: Kimura
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Yabuta
authors.forename: Shigeru
authors.initials: S
authors.lastname: Shigeoka
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D004777:Environment; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D016601:RNA-Binding Proteins; C483303:SR45 protein, Arabidopsis