Scapinin, a putative protein phosphatase-1 regulatory subunit associated with the nuclear nonchromatin structure.
J Biol Chem
; 278(46): 45611-9, 2003 Nov 14.
Article
em En
| MEDLINE
| ID: mdl-12925532
ABSTRACT
It is thought that the nuclear nonchromatin structures, such as the nuclear matrix and lamina, play regulatory roles in gene expression. In this study, we identified an insoluble protein that was associated with the chromatin-depleted nuclear structure of proliferating human leukemia HL-60 cells. Preparation of the chromatin-depleted nuclear structure, referred to as the nuclear matrix-intermediate filament scaffold (Fey, E., Krochmalnic, G., and Penman, S. (1986) J. Cell. Biol. 102, 1654-1665), involved cell extraction using a series of buffers containing Triton X-100, DNase I, and 2 M NaCl. A yeast two-hybrid assay revealed that this protein bound to the catalytic subunit of protein phosphatase-1 (PP1). Furthermore, it inhibited PP1 activity in vitro. We therefore named it scapinin (scaffold-associated PP1 inhibiting protein). cDNA cloning revealed that scapinin had two splicing variants of 448 amino acids (scapinin-S) and 518 amino acids (scapinin-L). Scapinin was down-regulated by differentiation in HL-60 cells. These results suggest that scapinin is a putative regulatory subunit of PP1 and is involved in transformed or immature phenotypes of HL-60 cells. We also describe the presence of scapinin family proteins from worm to human.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas Nucleares
/
Núcleo Celular
/
Fosfoproteínas Fosfatases
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Japão