| Literature DB >> 17391644 |
Sunny J-S Yoo1, Joan M Boylan, David L Brautigan, Philip A Gruppuso.
Abstract
The prototypical form of the Ser/Thr phosphatase PP2A is a heterotrimeric complex consisting of catalytic subunit (C), and A and B regulatory subunits. C-terminal methylation of PP2A-C influences holoenzyme assembly. Using late gestation development in the rat as an in vivo model of liver growth, we found that PP2A-C protein and activity levels were higher in fetal compared to adult liver extracts. However, unmethylated PP2A-C was much higher in the adult extracts. In MonoQ fractionation, unmethylated C eluted separately from methylated C, which was present predominantly in ABC heterotrimers. Gel filtration chromatography revealed that some unmethylated C was present as free catalytic subunit in adult liver. In addition, a significant proportion of PP2A was in inactive forms that may involve novel regulatory subunits. Our results indicate that methylation of PP2A-C appears to be a primary determinant for the biogenesis of PP2A heterotrimers.Entities:
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Year: 2007 PMID： 17391644 PMCID： PMC1868455 DOI： 10.1016/j.abb.2007.02.019
Source DB: PubMed Journal: Arch Biochem Biophys ISSN： 0003-9861 Impact factor: 4.013