A role for the p34cdc2 kinase and phosphatases in the regulation of phosphorylation and disassembly of lamin B2 during the cell cycle

Luscher, B., Brizuela, L., Beach, D., Eisenman, R. N. (April 1991) A role for the p34cdc2 kinase and phosphatases in the regulation of phosphorylation and disassembly of lamin B2 during the cell cycle. EMBO J, 10 (4). pp. 865-75. ISSN 0261-4189 (Print)0261-4189 (Linking)

URL: http://www.ncbi.nlm.nih.gov/pubmed/1849074

Abstract

While the p34cdc2 kinase is considered to be a critical regulator of mitosis, its function has not yet been directly linked to one of the key events during the onset of mitosis: nuclear envelope breakdown. Here we show that a major structural protein of the nuclear envelope, lamin B2, is phosphorylated by p34cdc2. Results from two-dimensional phosphopeptide mapping experiments demonstrate that the p34cdc2-specific phosphopeptides represent both mitotic and interphase specific phosphorylations of lamin B2 and include the major interphase phosphorylation site. In mitotic cells we detected two distinct forms of lamin B2 which differ in electrophoretic mobility and in degree of phosphorylation. The phosphorylation pattern of lamin B2 generated in vitro by p34cdc2 was more closely related to the less phosphorylated mitotic lamin B2, suggesting that another kinase(s) in addition to p34cdc2 is involved in generating the mitotic phosphorylation pattern. In addition, we show that treatment of interphase cells with okadaic acid, a potent phosphatase inhibitor, leads to the acquisition of mitosis-specific phosphopeptides and can reversibly increase the detergent-solubility of lamin B2. However, the M-phase-like phosphorylation of lamin B2 in itself is not sufficient to induce its disassembly from the nuclear lamina suggesting that an additional event(s) besides phosphorylation is required.

Item Type: Paper
Uncontrolled Keywords: Animals CDC2 Protein Kinase/*metabolism *Cell Cycle/drug effects Cell Line Ethers, Cyclic/pharmacology *Lamin Type B Lamins Nuclear Envelope/ultrastructure Nuclear Proteins/*metabolism Okadaic Acid Peptide Mapping Phosphopeptides/isolation & purification Phosphoric Monoester Hydrolases/*metabolism Phosphorylation
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > cdc2
organs, tissues, organelles, cell types and functions > cell types and functions > cell functions > cell cycle
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > kinase
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein expression > phosphorylation
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > protein phosphatase
CSHL Authors:
Communities: CSHL labs > Beach lab
Depositing User: Matt Covey
Date: April 1991
Date Deposited: 16 Dec 2015 20:53
Last Modified: 16 Dec 2015 20:53
PMCID: PMC452727
URI: http://repository.cshl.edu/id/eprint/32135

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