Nuclear accumulation of G-actin in cellular senescence: Reduced expressions of exportin 6 and Ran small G protein

Actin is a highly conserved, ubiquitous cytoskeletal protein, which contains two leucine-rich nuclear export signal (NES) sequences in the middle of the molecule. It has been known that actin is exclusively kept in the cytoplasm by exportin 1 (CRM1)-driven nuclear export. However, CRM1 has been reported to be not directly involved in actin export from vertebrate or Drosophila nuclei. On the other hand, exportin 6 (exp6) has been found as a novel family member from higher eukaryotes. Exp6 mediates nuclear export of profilin-actin complexes. We earlier reported that actin was accumulated in nucleus during replicative senescence of human diploid fibroblast (HDF). In the present study, we found that the increase of doubling time of HDF cells decreased exp6 and Ran expression as well as phosphorylated cofilin. Concurrently, Ran was transported into the cytoplasm. We attempted to determine possible involvement of exp6 in the regulation of actin accumulation in nuclei, by employing H₂O₂-induced senescent model. Exp6 and Ran expressions were not changed and Ran was localized in cytoplasm. Phosphorylated cofilin was decreased in induced senescent cells. These results suggest that exp6, Ran and cofilin are involved in the regulation of actin accumulation in nuclei during cellular senescence.

Author dc:creator

• 박, 수현

Contributors dc:contributor

• 임, 인경
• 대학원 의학과
• 200624278

• Exportin 6
• actin
• Ran

Language dc:language

ko

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000009206
000000009206

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/1808