Alternative splicing regulates the production of ARD-1 endoribonuclease and NIPP-1, an inhibitor of protein phosphatase-1, as isoforms encoded by the same gene.
ARD-1 is an endoribonuclease identified initially as the product of a human cDNA that complements mutations in rne, a gene that encodes Escherichia coli ribonuclease E. NIPP-1 was identified in bovine nuclear extracts as an inhibitor of protein phosphatase-1. Earlier work has shown that the protein-coding sequence of ARD-1 is identical to the carboxy-terminal third of NIPP-1. However, whether ARD-1 is present in eukaryotes as a distinct entity has been unclear, as neither ARD-1-specific transcripts nor ARD-1 protein were detected in mammalian cells in earlier studies. Here we show that ARD-1 exists in human cells as a discrete protein, and that the ARD-1 and NIPP-1 peptides are isoforms encoded by a single gene and the same alternatively spliced precursor RNA. A retained intron containing multiple translation stop codons that are configured to terminate translation and initiate nonsense-mediated decay, limits the production of cellular ARD-1 protein. Our results establish the process by which functionally disparate ARD-1 and NIPP-1 peptides are generated from the protein-coding sequence of the same gene in human cells.
Chang
A C
AC
MRC Protein Phosphorylation Unit, Department of Biochemistry, University of Dundee, Dundee, UK.
Sohlberg
B
B
Trinkle-Mulcahy
L
L
Claverie-Martin
F
F
Cohen
P
P
Cohen
S N
SN
D017398:Alternative Splicing; D001483:Base Sequence; D002352:Carrier Proteins; D002457:Cell Extracts / Q000737:chemistry; D002460:Cell Line; D002461:Cell Line, Transformed; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004722:Endoribonucleases / Q000235:genetics*; D005091:Exons; D005786:Gene Expression Regulation; D005796:Genes / Q000235:genetics; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007438:Introns; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors; D020033:Protein Isoforms / Q000235:genetics; D054645:Protein Phosphatase 1; D012322:RNA Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D002457:Cell Extracts; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D020033:Protein Isoforms; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C021042:protein phosphatase inhibitor-1; D004722:Endoribonucleases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; C097081:PPP1R8 protein, human