NSSRs/TASRs/SRp38s function as splicing modulators via binding to pre-mRNAs.
The genes for neural-salient serine/arginine-rich (NSSR) proteins 1 and 2 have been cloned from the neuronal differentiated embryocarcinoma cell line, P19. NSSRs contain an RNA recognition motif (RRM) at the N-terminal and several SR rich regions at the C-terminal resembling RS domains. We found that NSSRs associated with U1-70k, and determined the exon inclusion activity of NSSRs' C-terminals. First, the RRM was changed to the MS2 coat protein (MS2CP) and then, MS2 RNA stem-loops were inserted in the middle of the exon N of the clathrin light chain B minigene as an artificial exonic splicing enhancer to be recognized by the MS2CP. The modified exon N of the pre-mRNA was included by the MS2CP switched NSSR 1, but it was excluded by the MS2CP switched NSSR 2. The deletion analysis of the MS2CP switched NSSR 1 showed that the middle SR rich region was responsible for the activity of the modified exon N inclusion. Furthermore, the RRM domain of NSSRs recognized mRNAs. NSSRs were expressed in the nervous system, especially in cerebellar and hippocampal primordia, ventricular zone of the neocortex and olfactory bulb primordia, retina, and olfactory epithelium at E15.5, all containing undifferentiated neural stem cells. Taken together, our results showed that NSSRs modulate alternative splicing via binding to premRNAs during neural differentiation.
Fushimi
Kazuo
K
Center for Nano Materials and Technology, Japan Advanced Institute of Science and Technology, Nomi-City, Ishikawa 923-1292, Japan.
Osumi
Noriko
N
Tsukahara
Toshifumi
T
D017398:Alternative Splicing; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D036022:Capsid Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D005091:Exons; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D017434:Protein Structure, Tertiary; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D012694:Serine / Q000235:genetics; D020798:Two-Hybrid System Techniques
D036022:Capsid Proteins; D018797:Cell Cycle Proteins; C485446:Fusip1 protein, mouse; D009363:Neoplasm Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; D012694:Serine