Protein: Telomere-associated protein RIF1 (Rap1 interacting factor 1) (Q9XZ34)
Organism: Drosophila melanogaster (Fruit fly)
Function: Regulates the timing of initiation of DNA replication. Functions in copy number control by promoting the underreplication of DNA, which is found in many late replicating euchromatic regions of salivary gland polytene chromosomes. Promotes underreplication by localizing to active DNA replication forks in a partially SuUR-dependent manner, and inhibiting replication fork progression. Might also work as an adapter to recruit Pp1-87B to multiple sites on the chromosome and may function with Pp1-87B to mediate underreplication. Plays an essential role in embryonic development, in the transition from larvae to pupae and, probably, in proliferating tissues later on. In embryos, during mid-blastula transition, binds to and selectively delays the replication of large blocks of repetitive DNA satellite sequences during S phase in response to the activity of Cdk1; maternal Rif1 is specifically required for the normal extension of S phase 14. Unlike mammalian orthologs, does not appear to play a role in DNA damage repair.
Subcellular location: Nucleus {ECO:0000269|PubMed:22712556, ECO:0000269|PubMed:26022086, ECO:0000269|PubMed:29746464, ECO:0000269|PubMed:30277458}. Chromosome {ECO:0000269|PubMed:22712556, ECO:0000269|PubMed:26022086, ECO:0000269|PubMed:29746464, ECO:0000269|PubMed:30277458}. Chromosome, telomere {ECO:0000269|PubMed:26022086}. Note=Localizes to heterochromatin in all stages of amplifying follicle cells and accumulates at active DNA replication forks in the later stages of DNA amplification (PubMed:30277458). Associates with polytene chromosomes in salivary glands (PubMed:26022086). Associates with heterochromatin in a dynamic manner in different mitotic stages of the cell cycle (PubMed:22712556, PubMed:26022086, PubMed:29746464, PubMed:30277458). Absent at metaphase chromosomes but re-associates with the condensed chromosomes during late anaphase (PubMed:22712556, PubMed:26022086, PubMed:29746464). During mid-blastula transition in the S phase of embryos, dissociates from chromatin before the replication of the bound DNA satellite sequences (PubMed:29746464). {ECO:0000269|PubMed:22712556, ECO:0000269|PubMed:26022086, ECO:0000269|PubMed:29746464, ECO:0000269|PubMed:30277458}.
Interaction partners:
- Protein suppressor of underreplication
- Double parked, isoform A
- Origin recognition complex subunit 1
- DNA replication licensing factor Mcm6
- ATP-dependent DNA helicase PIF1
Sequence:
MDVDFGAQAGQSYRTVQLSAKEVLAAGRRQHYCNMIDLLASSCKSSGLIATSFTDDELVEFWLGDILPLMFDADRKIQDCAVAALAEALVALDVSVIHSAKCWPQIRSEFVDKYTIIIGEMRDAKNSNWHKIWTLLVQIMDEDLLRGCVYINKFLALVELGFRNPDNGVRSEAFLCWRVLIKIFAAYDELTSAKRLRLLLIPLRTSQSRSSHVSGIKLRVWWYLLSCLDHELPKSFDSAVEHFLAFMLGGGPRNLATGLAHNYQTARELALPCLVALWGVESSEPLQRLMRELRLETLVQPSPLMSVEVFQQHWKPLLAAAVSGLKLLTENDATEAEQLLLQLLVRNLCLAMFRLAVAPFNVACCSEIEKILQAEDNSGGRVVRALFNTIAADNLVMERVSGSDHLDVLEAYLKLVLKSKTEVPAAILQRSIACIFAVDRIEANNQNEFRMLGSFAELLMQANDEEDFEGFAFKLQVWRQVSQALSNYLRNNALEYRVAHNASLLDTWLLWPLQTLAAFAGRRASNSFDASFCDQWRQLVNAGQNAPGRKKFLTDLKATLTDLLKSKDEPLFAELFDAYVTSLIKFGLCKEAPLYKDVFGLLQTIFEQPSSQKTLEACLNTLRNLVVELRQNELMVVFDSLKPTLSSGIQCWNKMKCEGGFLEEWKRGIQEKFRKLPMKTMANQLKELFKADDLFVIIPSVWSLNPEKLTDRQKERFAEKSDIPALYNDMSQSQDSASIKPWTPKKVVIAKSKQGELALTGKDDNGEVIDITASEESEKEPVRVDVVTPIRKKPGRKSQAQKELEAAARAASLAEEPPKRQTRTRAAQKETEQVAQPQPAFEPQLRSPKKLPPSPVVQSTAAAVKQAKVAKPTPVVVIAQSEDLFPEVAAEPEPQPEPVKKPDPVPETTQLTPPDVPLEAVPSTQLPGSSGDPAASAGAVAAGEMSPKKSGTRIYNLSSPPDRKQTNNSSSPTLRPKPTGHLTGRGAQLINMIRNKKLDAASGSPYACMSTSRLVHQVTPARAQDRAEQVSTPTSELNELTGTDHTSTPIQAPPSKDLLVFSKRLPSPSASPSVSILKRKLRCESLDDVTLDSPALKRKRVSFHDPPVSVTKEYLRDAEETRSSLKPKRCLLMDKVAQTTEMRQALRRRGRLDSIIEIERFASEQTARTATTDKSLDKSTGEAPEEDAFTSLKWNDTGNAHNISISEEPVKAMEVESELETAGQDLAIMDPEAALDLAVAQLPLESVLQRYFDKSPLKSAGMLAKFLSAQMTANEKLKTNVLETLSENHSKDFLDHAVRENLSSVVCDRLNPTSVLEYVCAKSKISASCRNGLLAQVPEILKSGPRSDSERLAFVQQLMVQCSPGDDLLLDLIDLLMRTRRERNNSTSTHISKGVVSAVGSPDNVAETAADSSSNL