{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Keplinger AJ"],"funding":["Cancer Research Foundation","National Institutes of Health","National Institute of General Medical Sciences","National Science Foundation"],"pagination":["111123"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC12860355"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["302(2)"],"pubmed_abstract":["While predominantly studied in cytoplasmic contexts, actin plays critical roles in the nucleus, regulating genome accessibility, transcription, and DNA repair. Cell-based studies have contributed to a widely accepted model in which the import factor importin 9 (IPO9) acts in concert with the actin filament-severing protein cofilin to transport actin into the nucleus. The classical nuclear localization signal on cofilin is thought to anchor IPO9 to cofilin-bound actin monomers, driving the formation of an import-competent tripartite actin-cofilin-IPO9 complex. Contrary to this established model of actin import, we demonstrate that IPO9 directly binds to monomeric actin with midnanomolar affinity and, rather than promoting IPO9-actin complex formation, cofilin competitively inhibits the bind"],"journal":["The Journal of biological chemistry"],"pubmed_title":["A revised model of nuclear actin import: Importin 9 competes with cofilin, profilin, and RanGTP for actin binding."],"pmcid":["PMC12860355"],"funding_grant_id":["R35-GM145373"],"pubmed_authors":["Ruthenburg AJ","Srinivasan PA","Keplinger AJ","Christensen SM","Suarez C"],"additional_accession":[]},"is_claimable":false,"name":"A revised model of nuclear actin import: Importin 9 competes with cofilin, profilin, and RanGTP for actin binding.","description":"While predominantly studied in cytoplasmic contexts, actin plays critical roles in the nucleus, regulating genome accessibility, transcription, and DNA repair. Cell-based studies have contributed to a widely accepted model in which the import factor importin 9 (IPO9) acts in concert with the actin filament-severing protein cofilin to transport actin into the nucleus. The classical nuclear localization signal on cofilin is thought to anchor IPO9 to cofilin-bound actin monomers, driving the formation of an import-competent tripartite actin-cofilin-IPO9 complex. Contrary to this established model of actin import, we demonstrate that IPO9 directly binds to monomeric actin with midnanomolar affinity and, rather than promoting IPO9-actin complex formation, cofilin competitively inhibits the bind","dates":{"release":"2025-01-01T00:00:00Z","publication":"2025 Dec","modification":"2026-06-12T10:15:29.187Z","creation":"2026-06-12T03:11:40.774Z"},"accession":"S-EPMC12860355","cross_references":{"pubmed":["41478570"],"doi":["10.1016/j.jbc.2025.111123"]}}