Rab34 GTPase mediates ciliary membrane biogenesis in the intracellular ciliogenesis pathway

2020 ◽  
Author(s):  
Nicola Stevenson
Keyword(s):  
Membrane Biogenesis ◽  
Ciliary Membrane

scholarly journals Cep164 mediates vesicular docking to the mother centriole during early steps of ciliogenesis

2012 ◽  
Vol 199 (7) ◽  
pp. 1083-1101 ◽  
Author(s):  
Kerstin N. Schmidt ◽  
Stefanie Kuhns ◽  
Annett Neuner ◽  
Birgit Hub ◽  
Hanswalter Zentgraf ◽  
...  
Keyword(s):  
Basal Body ◽  
Distal Part ◽  
Membrane Biogenesis ◽  
Step Process ◽  
Ciliary Membrane ◽  
Functional Assays ◽  
Apical Domain ◽  
Cilia Formation ◽  
Mother Centriole

Cilia formation is a multi-step process that starts with the docking of a vesicle at the distal part of the mother centriole. This step marks the conversion of the mother centriole into the basal body, from which axonemal microtubules extend to form the ciliary compartment. How vesicles are stably attached to the mother centriole to initiate ciliary membrane biogenesis is unknown. Here, we investigate the molecular role of the mother centriolar component Cep164 in ciliogenesis. We show that Cep164 was indispensable for the docking of vesicles at the mother centriole. Using biochemical and functional assays, we identified the components of the vesicular transport machinery, the GEF Rabin8 and the GTPase Rab8, as interacting partners of Cep164. We propose that Cep164 is targeted to the apical domain of the mother centriole to provide the molecular link between the mother centriole and the membrane biogenesis machinery that initiates cilia formation.

scholarly journals A Core Complex of BBS Proteins Cooperates with the GTPase Rab8 to Promote Ciliary Membrane Biogenesis

Cell ◽  
2007 ◽  
Vol 129 (6) ◽  
pp. 1201-1213 ◽  
Author(s):  
Maxence V. Nachury ◽  
Alexander V. Loktev ◽  
Qihong Zhang ◽  
Christopher J. Westlake ◽  
Johan Peränen ◽  
...  
Keyword(s):  
Membrane Biogenesis ◽  
Core Complex ◽  
Ciliary Membrane

scholarly journals Rab34 GTPase mediates ciliary membrane biogenesis in the intracellular ciliogenesis pathway

2020 ◽  
Author(s):  
Anil Kumar Ganga ◽  
Margaret C. Kennedy ◽  
Mai E. Oguchi ◽  
Shawn D. Gray ◽  
Kendall E. Oliver ◽  
...  
Keyword(s):  
Cell Surface ◽  
Primary Cilia ◽  
Mdck Cells ◽  
Membrane Biogenesis ◽  
Gtpase Domain ◽  
Ciliary Membrane ◽  
Gtp Binding ◽  
Mother Centriole ◽  
Context Specific ◽  
Intracellular Pathway

AbstractPrimary cilia form by two pathways: an extracellular pathway in which the cilium grows out from the cell surface and an intracellular pathway in which the nascent cilium forms inside the cell. Here we identify the GTPase Rab34 as a selective mediator of intracellular ciliogenesis. We find that Rab34 is required for formation of the ciliary vesicle at the mother centriole and that Rab34 marks the ciliary sheath, a unique sub-domain of assembling intracellular cilia. Rab34 activity is modulated by divergent residues within its GTPase domain, and ciliogenesis requires GTP binding and turnover by Rab34. Because Rab34 is found on assembly intermediates that are unique to intracellular ciliogenesis, we tested its role in the extracellular pathway used by MDCK cells. Consistent with Rab34 acting specifically in the intracellular pathway, MDCK cells ciliate independently of Rab34 and paralog Rab36. Together, these findings reveal a new context-specific molecular requirement for ciliary membrane biogenesis.

Role of the Cilia Membrane in Control of Microtubule Sliding

1980 ◽  
Vol 38 ◽  
pp. 612-615
Author(s):  
Edna S. Kaneshiro
Keyword(s):  
Control Mechanism ◽  
Beat Frequency ◽  
Surface Membrane ◽  
Ciliary Membrane ◽  
Ciliary Beating ◽  
Ciliary Reversal ◽  
Voltage Dependent ◽  
Reversal Mechanism ◽  
And Function

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+ concentrations. The Ca2+ levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+ conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+ current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+ by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6 M Ca2+ Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+ channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+ conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+ levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.

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