Regulator of chromosome condensation (RCC1)

Guanine-nucleotide releasing factor that promotes the exchange of Ran-bound GDP by GTP, and thus has an significant role in RAN-mediated functions in nuclear import and mitosis (PubMed:1944575, PubMed:17435751, PubMed:20668449, PubMed:22215983, PubMed:11336674). Contributes to the creation of high levels of chromosome-associated, GTP-bound RAN, which is important for mitotic spindle assembly and normal progress through mitosis (PubMed:12194828, PubMed:17435751, PubMed:22215983).

Via its role in maintaining high levels of GTP-bound RAN in the nucleus, contributes to the discharge of cargo proteins from importins after nuclear import (PubMed:22215983). Involved in the regulation of onset of chromosome condensation in the S phase (PubMed:3678831).