Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1987-5-6
pubmed:abstractText
Previous work from this laboratory has shown that approximately 24 proteins are reversibly modified by methyl esterification in a mouse lymphoma cell line. Here, we analyze several mouse tissues as well as other mouse, hamster, and human cell lines and find that many protein-methyl esters are ubiquitous while others show apparent tissue specificity. One of the modified proteins is identified by cellular localization and immunological detection as lamin B, a nuclear envelope structural protein which undergoes depolymerization during mitosis. The average stoichiometry of methylation is at least 0.5 methyl groups per lamin B molecule as determined by radioactive incorporation. By immunoblotting, however, demethylation appears to result in a gain of two negative charges suggesting the loss of two neutral methyl esters producing two carboxylic acid groups per molecule. By comparing mitotic and interphase cells, lamin B is found to be demethylated in mitosis while most other methyl esterified proteins show no appreciable cell cycle dependence. In addition to the correlation with cell cycle, it is shown that lamin B does not incorporate radioactive methyl esters in intact mouse brain tissue yet can do so if the cells are lysed. Analysis of lamin B charge by immunoblotting after isoelectric focusing indicates that this protein is fully methylated in brain suggesting that turnover of methyl groups in intact brain tissue is inhibited. We propose that methylation of lamin B may be involved in the control of disassembly and reassembly of the nuclear envelope during mitosis. If this were the case, the apparent lack of methyl group turnover in brain would be consistent with the inability of those cells to divide.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
262
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4303-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:3558408-Animals, pubmed-meshheading:3558408-Brain, pubmed-meshheading:3558408-Cell Cycle, pubmed-meshheading:3558408-Cell Line, pubmed-meshheading:3558408-Cricetinae, pubmed-meshheading:3558408-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:3558408-Esterification, pubmed-meshheading:3558408-Female, pubmed-meshheading:3558408-HeLa Cells, pubmed-meshheading:3558408-Humans, pubmed-meshheading:3558408-Isoelectric Focusing, pubmed-meshheading:3558408-Lamin Type B, pubmed-meshheading:3558408-Lamins, pubmed-meshheading:3558408-Liver, pubmed-meshheading:3558408-Lymphoma, pubmed-meshheading:3558408-Methylation, pubmed-meshheading:3558408-Mice, pubmed-meshheading:3558408-Neuroblastoma, pubmed-meshheading:3558408-Nucleoproteins, pubmed-meshheading:3558408-Ovary, pubmed-meshheading:3558408-Tissue Distribution
pubmed:year
1987
pubmed:articleTitle
Cell cycle-dependent methyl esterification of lamin B.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.