BBS5

Cilia effects upon perturbation of BBS5

Cilia number / % ciliated:

Decreased cilia number

Loss-of-function effect:

Longer cilia

Ciliogenesis screen results (5 screens)

• Kim2016: Not Reported
• Wheway et al. 2015 (siRNA) [siRNA]: Ciliogenesis Defect (z=-3.16) PMID:26167766
• Breslow et al. 2018 (CRISPR) [CRISPR]: Positive Regulator (Hh signaling, casTLE effect=-3.28) PMID:29459680
• Roosing et al. 2015 (siRNA) [siRNA]: No effect PMID:26595381
• Elliott et al. 2025 (CRISPRa) [CRISPRa]: Disassembly Trigger (casTLE Effect=-5.58) PMID:41160700

Phenotypes

Mouse phenotype:

increased total body fat amount, increased fasting circulating glucose level, increased monocyte cell number, decreased bone mineral content, impaired glucose tolerance, decreased grip strength, abnormal bone structure, increased circulating alkaline phosphatase level, decreased lean body mass, increased hematocrit, decreased heart weight, decreased respiratory quotient, increased circulating glucose level, tremors, decreased bone mineral density, increased leukocyte cell number, increased circulating fructosamine level, abnormal gait, increased hemoglobin content, thrombocytopenia, decreased circulating triglyceride level, increased lymphocyte cell number, decreased spleen weight, increased mean corpuscular volume

Human ciliopathy phenotype:

Bardet-Biedl syndrome 5; Bardet-Biedl syndrome; Bardet-Biedl syndrome 1

Ciliopathy associations

• Bardet-Biedl Syndrome

References: PMID:25982971, PMID:20177705, PMID:15137946, PMID:18203199

Subcellular localization

basal body, cilia

References: PMID:41005307, PMID:15137946, PMID:20603001, PMID:17574030, PMID:22072986, PMID:37240074

Functional category

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

Function

Mutated in Bardet-Biedl syndrome (type 5) (OMIM :603650 ,PMID:15137946). Forms part of BBSome, mediates binding to phospholipids, predominantly phosphatidylinositol 3- phosphate (20603001,PMID:17574030,PMID:22072986). Investigation of the cilia length in patient fibroblasts revealed that the mean ciliary length was significantly shorter in BBS1−/− cells (3.11 µm), whereas BBS5−/− (4.31–4.14 µm) and BBS10−/− (3.8–4.4 µm) all had significantly longer cilia compared to the pool of control cells (3.61 µm) (https://doi.org/10.3390/ijms22031345). BBS5 variants identified in our patient led to a significant decrease of cilium formation and a longer cilia length(PMID: 37240074)