IFT54 regulates IFT20 stability but is not essential for tubulin transport during ciliogenesis.

IFT54 regulates IFT20 stability but is not essential for tubulin transport during ciliogenesis.
Cell Mol Life Sci. 2017 Apr 17;:
Authors: Zhu X, Liang Y, Gao F, Pan J
Abstract
Intraflagellar transport (IFT) is required for ciliogenesis by ferrying ciliary components using IFT complexes as cargo adaptors. IFT54 is a component of the IFT-B complex and is also associated with cytoplasmic microtubules (MTs). Loss of IFT54 impairs cilia assembly as well as cytoplasmic MT dynamics. The N-terminal calponin homology (CH) domain of IFT54 interacts with tubulins/MTs and has been proposed to transport tubulin during ciliogenesis, whereas the C-terminal coiled-coil (CC) domain binds IFT20. However, the precise function of these domains in vivo is not well understood. We showed that in Chlamydomonas, loss of IFT54 completely blocks ciliogenesis but does not affect spindle formation and proper cell cycle progression, even though IFT54 interacts with mitotic MTs. Interestingly, IFT54 lacking the CH domain allows proper flagellar assembly. The CH domain is required for the association of IFT54 with the axoneme but not with mitotic MTs, and also regulates the flagellar import of IFT54 but not IFT81 and IFT46. The C-terminal CC domain is essential for IFT54 to bind IFT20, and for its recruitment to the basal body and incorporation into IFT complexes. Complete loss of IFT54 or the CC domain destabilizes IFT20. ift54 mutant cells expressing the CC domai...

Source: Cellular and Molecular Life Sciences : CMLS - April 17, 2017 Category: Cytology Authors: Zhu X, Liang Y, Gao F, Pan J Tags: Cell Mol Life Sci Source Type: research