Exp Mol Med.  2011 Jul;43(7):389-392. 10.3858/emm.2011.43.7.042.

p41-Arc, a regulatory subunit of Arp2/3 complex, can induce premature senescence in the absence of p53 and Rb

• Yun UJ
• Park SE
• Shin DY

• KMID: 1015457
• DOI: http://doi.org/10.3858/emm.2011.43.7.042

Abstract

Cellular senescence is a tumor-suppressive process instigated by proliferation in the absence of telomere replication, by cellular stresses such as oncogene activation, or by activation of the tumor suppressor proteins, such as Rb or p53. This process is characterized by an irreversible cell cycle exit, a unique morphology, and expression of senescence-associated-beta-galactosidase (SA-beta-gal). Despite the potential biological importance of cellular senescence, little is known of the mechanisms leading to the senescent phenotype. p41-Arc has been known to be a putative regulatory component of the mammalian Arp2/3 complex, which is required for the formation of branched networks of actin filaments at the cell cortex. In this study, we demonstrate that p41-Arc can induce senescent phenotypes when it is overexpressed in human tumor cell line, SaOs-2, which is deficient in p53 and Rb tumor suppressor genes, implying that p41 can induce senescence in a p53-independent way. p41-Arc overexpression causes a change in actin filaments, accumulating actin filaments in nuclei. Therefore, these results imply that a change in actin filament can trigger an intrinsic senescence program in the absence of p53 and Rb tumor suppressor genes.

Keyword

p41-Arc; Arp2/3; p53; senescence

MeSH Terms

Actin Cytoskeleton/metabolism
Actin-Related Protein 2-3 Complex/*metabolism
*Cell Aging
Cell Cycle Proteins/metabolism
Cell Line, Tumor
Cell Nucleus/metabolism
Fibroblasts/physiology
Humans
Recombinant Proteins/genetics/*metabolism
Retinoblastoma Protein/*deficiency/genetics
Tumor Suppressor Protein p53/*deficiency/genetics