Detection of multiple splice variants of the nuclear protein phosphatase 1 regulator sds22 in rat liver nuclei

• Published in: Biochemistry and cell biology Vol. 80; no. 6; pp. 811 - 815
• Main Authors: Tran, Hue T, Bridges, Dave, Ulke, Annegret, Moorhead, Greg B.G
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.01.2002; Canadian Science Publishing NRC Research Press
• Subjects: Alternative Splicing; Amino Acid Sequence; Animals; Blotting, Western; Cell Cycle Proteins - analysis; Cell Cycle Proteins - chemistry; Cell Cycle Proteins - genetics; Cell Cycle Proteins - isolation & purification; Cell Nucleus - chemistry; Cell Nucleus - enzymology; Cells; Cellular biology; Liver - chemistry; Liver - enzymology; Male; Metabolic disorders; Microcystins; Molecular Sequence Data; Molecular Weight; Nuclear Proteins; Peptides; Phosphatase; Phosphoprotein Phosphatases - chemistry; Phosphoprotein Phosphatases - isolation & purification; Protein Phosphatase 1; Proteins; Rats; Rats, Sprague-Dawley; Rodents; Sequence Homology, Amino Acid; Yeast
• ISSN: 0829-8211; 1208-6002
• DOI: 10.1139/o02-155

Antipeptide antibodies generated against the N terminus of the protein phosphatase 1 (PP1) binding protein sds22 detected at least four forms of the protein in a rat liver nuclear extract. Four of these immunoreactive bands likely correspond to four predicted forms of sds22 that are generated by alternative splicing. These four proteins are expressed at different levels and appear to be localized exclusively in the nucleus, and two of these proteins copurify with PP1 on the protein phosphatase affinity matrix microcystin–Sepharose. Two higher molecular mass nuclear proteins that are immunoreactive with the sds22 antibodies also copurify on microcystin–Sepharose and may be novel forms of sds22 expressed in mammalian cells.Key words: sds22, protein phosphatase 1 (PP1), nucleus, microcystin–Sepharose.