Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-4-24
pubmed:abstractText
Protein phosphatase 2A (PP2A) is a heterotrimeric enzyme consisting of a catalytic subunit (C), a structural subunit (A), and a variable regulatory subunit (B). We have investigated the spatial and temporal expression patterns of three members of the B subunit family, Balpha, Bbeta, and Bgamma, both at the message level by using ribonuclease protection analysis and at the protein level by using specific antibodies. Although A, Balpha, and C protein are expressed in many tissues, Bbeta and Bgamma were detectable only in brain. Balpha, Bbeta, and Bgamma are components of the brain PP2A heterotrimer, because they copurified with A and C subunits on immobilized microcystin. Whereas Balpha and Bbeta are mainly cytosolic, Bgamma is enriched in the cytoskeletal fraction. In contrast to A, C, and Balpha, which are expressed at constant levels, Bbeta and Bgamma RNA and protein are developmentally regulated, with Bbeta levels decreasing and Bgamma levels increasing sharply after birth. RNA and immunoblot analyses of subdissected brain regions as well as immunohistochemistry demonstrated that B subunits are expressed in distinct but overlapping neuronal populations and cellular domains. These data indicate that B subunits confer tissue and cell specificity, subcellular localization, and developmental regulation to the PP2A holoenzyme. The Balpha-containing heterotrimer may be important in general neuronal functions that involve its partially nuclear localization. Holoenzymes containing B likely function in early brain development as well as in somata and processes of subsets of mature neurons. Bgamma may target PP2A to cytoskeletal substrates that are important in the establishment and maintenance of neuronal connections.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9967
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
392
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
515-27
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:9514514-Amino Acid Sequence, pubmed-meshheading:9514514-Animals, pubmed-meshheading:9514514-Antibody Specificity, pubmed-meshheading:9514514-Brain, pubmed-meshheading:9514514-COS Cells, pubmed-meshheading:9514514-Cell Compartmentation, pubmed-meshheading:9514514-Gene Expression Regulation, Developmental, pubmed-meshheading:9514514-Gene Expression Regulation, Enzymologic, pubmed-meshheading:9514514-Immunohistochemistry, pubmed-meshheading:9514514-Molecular Sequence Data, pubmed-meshheading:9514514-Phosphoprotein Phosphatases, pubmed-meshheading:9514514-Phosphorylation, pubmed-meshheading:9514514-Protein Phosphatase 2, pubmed-meshheading:9514514-RNA, Messenger, pubmed-meshheading:9514514-Rats, pubmed-meshheading:9514514-Rats, Sprague-Dawley, pubmed-meshheading:9514514-Signal Transduction, pubmed-meshheading:9514514-Subcellular Fractions
pubmed:year
1998
pubmed:articleTitle
Brain protein phosphatase 2A: developmental regulation and distinct cellular and subcellular localization by B subunits.
pubmed:affiliation
Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't