Regulator of telomere elongation helicase 1 (RTEL1) is a animal functional analogue of yeast Srs2, which is a DNA helicase and DNA-dependent ATPase involved in DNA repair and checkpoint recovery []. RTEL1 is an essential DNA helicase that disassembles a variety of DNA secondary structures to facilitate DNA replication, repair, and recombination processes, and to maintain telomere integrity [, , ]. It is recruited by Trf2 to telomeres in S phase to promote T-Loop unwinding []. It is also required for the export and the correct cytoplasmic trafficking of the small nuclear (sn) RNA pre-U2, a component of themajor spliceosome complex []. Constitutional mutations in the RTEL1 gene cause Hoyeraal-Hreidarsson syndrome (HHS), a severe form of Dyskeratosis congenita characterised by developmental defects, bone marrow failure and immunodeficiency and has been associated with telomere dysfunction [, ].
This entry includes a group of ATP-dependent helicases, including Rad3/XPD (ERCC2), Chl1/DDX11, DDX12, RTEL1 and BRIP1. Rad3/XPD is a subunit of RNA polII initiation factor TFIIH and of Nucleotide Excision Repair Factor 3 (NEF3) [, ]. DDX11/Chl1 is required for sister-chromatid cohesion [, , ]. Defects in DDX11 are the cause of Warsaw breakage syndrome (WBRS). It is a syndrome characterised by severe microcephaly, pre- and postnatal growth retardation, facial dysmorphism and abnormal skin pigmentation [].
