Human DNA helicase, RuvBL1 and its Chlamydomonas homologue, CrRuvBL1 plays an important role in ciliogenesis

Abstract

Several nuclear and nucleic acid-binding proteins were detected in the proteomic analyses of ciliary fractions from various organisms. Yet very little is known about the role of these proteins in ciliogenesis and ciliary signaling. In an attempt to characterize the role of these nuclear proteins, we identified a hypothetical protein from Chlamydomonas reinhardtii, CrRuvBL1, which is homologous to human DNA helicase, HsRuvBL1. CrRuvBL1 localizes to flagella and nucleus in vegetative Chlamydomonas cells. It accumulates in the nucleus specifically during initial stages of flagellar assembly and cell division indicating its role in these processes. Mammalian counterpart of this protein, HsRuvBL1, was found to be present at the basal bodies and in the primary cilium of quiescent Retinal Pigment Epithelial (RPE1) cells. In interphase cells, HsRuvBL1 is present at centrioles while the protein localizes on spindle fibers, spindle poles and midbodies, which are important structures formed during different phases of cell division. Depletion of HsRuvBL1 by using siRNAs leads to complete loss of primary cilia in RPE1 cells. Together these results suggest that nuclear proteins play an important role in ciliogenesis.

Role of the Novel Hsp90 Co-Chaperones in Dynein Arms’ Preassembly

“…Immunofluorescence analysis of mouse ependymal and oviduct epithelial multiciliated cells, as well as studies of Kupffer's vesicle and pronephric ciliated cells in zebrafish, showed that RuvBL1 was present in the cytoplasm [15,49] and in the nucleus [49]. Contradictory to these data, using a non-commercial antibody, it was shown that in Chlamydomonas RuvBL1 was also present in flagella [50].…”

Suramin action in African trypanosomes involves a RuvB-like DNA helicase

“…RuvB-like DNA helicases have been well studied in bacteria ( Iwasaki et al, 1992 ; Shinagawa et al, 1991 ; Yamada et al, 2001 ). In eukaryotes, the proteins RuvB-like 1 and RuvB-like 2 are also called pontin and reptin ( Jha and Dutta, 2009 ), respectively, and they have acquired additional functions including DNA repair and chromatin remodelling ( Dauden et al, 2021 ; Tammana and Tammana, 2017 ). A chromatin remodelling complex from T. brucei , which contains TbRuvBL1 and TbRuvBL2, has been described recently ( Vellmer et al, 2022 ).…”

Suramin action in African trypanosomes involves a RuvB-like DNA helicase

“…RuvB-like DNA helicases have been well studied in bacteria (Shinagawa, 1991;Iwasaki, 1992;Yamada, 2001). In eukaryotes, the proteins RuvB-like 1 and RuvBlike 2 are also called pontin and reptin (Jha, 2009), respectively, and they have acquired additional functions including DNA repair and chromatin remodeling (Tammana, 2017;Dauden, 2021). A chromatin remodelling complex from T. brucei, which contains TbRuvBL1 and TbRuvBL2, has been described recently (Vellmer, 2022).There is to our knowledge only one experimental study from trypanosomatids, where LmRUVBL1 and LmRUVBL2 from Leishmania major were recombinantly (co-)expressed.…”