Open AccessLAP2α-binding protein LINT-25 is a novel chromatin-associated protein involved in cell cycle exit
Author(s) -
Naetar,
Sabine A. Hutter,
D. Dorner,
Thomas Dechat,
Barbara Korbei,
Josef Gotzmann,
Hartmut Beug,
Roland Foisner
Publication year - 2007
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.03390
Subject(s) - microbiology and biotechnology , biology , cell cycle , lint , chromatin , retinoblastoma protein , downregulation and upregulation , lamin , cell , genetics , dna , gene , nucleus , agronomy
Lamina-associated polypeptide 2α (LAP2α) is a nuclear protein dynamically associating with chromatin during the cell cycle. In addition, LAP2α interacts with A-type lamins and retinoblastoma protein and regulates cell cycle progression via the E2F-Rb pathway. Using yeast two-hybrid analysis and three independent in vitro binding assays we identified a new LAP2α interaction partner of hitherto unknown functions, which we termed LINT-25. LINT-25 protein levels were upregulated during G1 phase in proliferating cells and upon cell cycle exit in quiescence, senescence and differentiation. Upon cell cycle exit LINT-25 accumulated in heterochromatin foci, and LAP2α protein levels were downregulated by proteasomal degradation. Although LAP2α was not required for the upregulation and reorganization of LINT-25 during cell cycle exit, transient expression of LINT-25 in proliferating cells caused loss of LAP2α and subsequent cell death. Our data show a role of LINT-25 and LAP2α during cell cycle exit, in which LINT-25 acts upstream of LAP2α.