RAB18

Cilia effects upon perturbation of RAB18

Cilia number / % ciliated:

No effect

Loss-of-function effect:

No effect

Ciliogenesis screen results (3 screens)

• Wheway et al. 2015 (siRNA) [siRNA]: Ciliogenesis Defect (z=-6.01) PMID:26167766
• Breslow et al. 2018 (CRISPR) [CRISPR]: No Significant Effect PMID:29459680
• Roosing et al. 2015 (siRNA) [siRNA]: No effect PMID:26595381

Phenotypes

Mouse phenotype:

limb grasping, impaired pupillary reflex, decreased circulating creatinine level

Ciliopathy associations

• Warburg Micro Syndrome

Subcellular localization

ciliary membrane

Functional category

• Ciliary assembly/disassembly
• Trafficking (BBSome, small GTPases, vesicular transport, ATPases)
• Ciliary membrane

Function

Chlamydomonas RAB18 is dispensable for ciliation and IFT. (A). RAB18miR cells assemble cilia with normal length. Representative differential interreference contrast images of CC-5325 and RAB18miR cells are shown. The number of cells with cilia out of fifty counted cells is listed for each strain. Scale bar: 10 µm. (B). RAB18miR cells had full-length cilia (11.49 ± 0.55 µm, n = 50) compared to CC-5325 cells (11.35 ± 0.94 µm, n = 50). Mean lengths are listed, error bar indicates S.D., and “n” indicates the number of cilia counted and listed in each bar. “n.s.” denotes non- significance. A two-tailed t-test is used for statistical analysis.Upon crossing the TZ and reaching the proximal ciliary region, RAB18-GTP undergoes rapid nucleotide exchange, converting to RAB18-GDP. This conversion causes RAB18-GDP to detach from the ciliary membrane and localize within the ciliary matrix.