| Aspect | BBS10 summary | Evidence / details | Key citations |
|---|---|---|---|
| Verified identity | **BBS10** encodes **Bardet-Biedl syndrome 10 protein** in **Homo sapiens**; it is a **chaperonin-like BBS protein** rather than a core BBSome subunit. | Reviews and gene tables consistently classify BBS10 with **BBS6/MKKS** and **BBS12** as BBSome assembly chaperonins, distinct from the 8-subunit BBSome. This matches the UniProt description and TCP-1/CCT family assignment. | (pqac-00000009, pqac-00000011, pqac-00000024) |
| Primary molecular function | **Mediator/regulator of BBSome assembly** through a **chaperonin-like role**; supports formation of the BBSome rather than acting as a cargo-binding BBSome subunit itself. | BBS10 forms part of a specialized **BBS/CCT assembly machinery** required for BBSome biogenesis. Loss of this machinery disrupts assembly of the BBSome and destabilizes BBSome subunits. | (pqac-00000012, pqac-00000020, pqac-00000022) |
| Protein family and structural class | **Chaperonin-like protein** with homology to **group II chaperonins / CCT(TRiC)/TCP-1 family**. | BBS10 is repeatedly described as having sequence and structural homology to CCT family chaperonins, placing it in the eukaryotic type II chaperonin lineage, but with specialized BBS-related function. | (pqac-00000002, pqac-00000011, pqac-00000022, pqac-00000024) |
| Domain architecture | Contains the canonical chaperonin-like **apical, intermediate, and equatorial domains**. | Review evidence explicitly states that BBS10 has **three functional domains**: **apical**, **intermediate**, and **equatorial**. The equatorial/intermediate region is linked to ATP-related motifs in canonical chaperonins, though bona fide ATPase activity for BBS10 remains unvalidated. | (pqac-00000019, pqac-00000023) |
| Functional meaning of domains | **Apical domain** likely contributes to client/substrate interactions; **intermediate/equatorial domains** retain chaperonin-like architecture but do not establish canonical ATP-dependent folding activity. | BBS10 truncating variants in the **intermediate** and **equatorial** domains are predicted to disrupt regions classically responsible for ATP binding/hydrolysis and folding in canonical chaperonins; however, reviews emphasize that BBS10 is **unlikely to function as a classical ATP-driven chaperonin**. | (pqac-00000002, pqac-00000019, pqac-00000024) |
| ATPase / catalytic status | **No confirmed classical enzymatic/chaperonin ATPase activity**. | Reviews note that while canonical CCT chaperonins fold substrates in an ATP-dependent manner, the **ATPase activity of BBS10 has not been validated**; BBS6/BBS12 lack conserved ATP-binding features, and BBS10 is considered only partially conserved at this motif. | (pqac-00000002, pqac-00000012, pqac-00000023) |
| Mechanistic role in assembly | **Regulates formation of the BBS-chaperonin complex** and promotes early steps of BBSome assembly by enabling **BBS7 stabilization** and its productive association with **BBS2**. | A stepwise assembly model places BBS10 upstream of the BBSome core: BBS10 helps establish/organize the BBS6-BBS12-CCT system, which stabilizes **BBS7** and promotes formation of the **BBS2-BBS7-BBS9 core complex**, followed by recruitment of additional BBSome subunits. | (pqac-00000012, pqac-00000020, pqac-00000022) |
| Assembly pathway position | Functions at an **early initiation step** of BBSome biogenesis. | Because BBS6/BBS10/BBS12 account for a large fraction of BBS cases and are required before stable BBSome formation, they are inferred to act early; mechanistic work places BBS10 before or during transition from the BBS-chaperonin complex to the BBS2-BBS7-BBS9 core intermediate. | (pqac-00000011, pqac-00000012, pqac-00000024) |
| Chaperonin complex membership | Participates in a **higher-order complex** with **BBS6**, **BBS12**, and **CCT/TRiC family chaperonins**. | Sequential purification and gel filtration identified a complex containing the three chaperonin-like BBS proteins plus multiple **CCT** subunits. This complex is necessary for BBSome assembly. | (pqac-00000021, pqac-00000022) |
| CCT/TRiC interaction partners | Associated with **CCT1, CCT2, CCT3, CCT4, CCT5, and CCT8** in the BBS/CCT assembly complex. | Primary data and later reviews state that BBS6/BBS10/BBS12 form a complex with six canonical CCT chaperonins; this is the core evidence linking BBS10 to the TCP-1 family functionally as well as evolutionarily. | (pqac-00000012, pqac-00000021, pqac-00000022) |
| Direct/near-direct BBSome-related partners | Interacts with **BBS7**; reported interactions also include **BBS9** and association with assembly intermediates containing **BBS2**. | Co-IP studies summarized in reviews found BBS10 interaction with **BBS7** and **BBS9**; mechanistically, the chaperonin complex promotes BBS7 stability and BBS7-BBS2 association, enabling BBSome core formation. | (pqac-00000002, pqac-00000012, pqac-00000021) |
| Role relative to BBS7 | **BBS7 is a key client/assembly substrate** whose stabilization depends on the BBS-chaperonin machinery involving BBS10. | The BBS-chaperonin complex plays a role in **BBS7 stability**; BBS7 then joins BBS2 and BBS9 to form the core intermediate. Reviews further state that BBS6/BBS10/BBS12 act as a substrate-binding unit linking CCT chaperonins to BBS7. | (pqac-00000002, pqac-00000012, pqac-00000020) |
| Not a structural BBSome subunit | **Excluded from the mature octameric BBSome**. | The mature BBSome is composed of BBS1, BBS2, BBS4, BBS5, BBS7, BBS8/TTC8, BBS9, and BBS18/BBIP1; BBS10 instead belongs to the assembly machinery. | (pqac-00000001, pqac-00000005, pqac-00000011) |
| Subcellular localization | Best-supported localization is **basal body / pericentriolar region**; unlike core BBSome proteins, chaperonin-like BBS proteins are generally **not detected along the primary cilium** itself. | Reviews note that chaperonin-like BBS proteins have **not been detected along the primary cilium**, but have been found at the **basal body**. BBS10 protein was detected at the basal body of **ciliated IMCD cells**. | (pqac-00000003, pqac-00000019) |
| Cellular site of action | Functions mainly in the **cytoplasm/pericentriolar compartment at or near the basal body**, where pre-BBSome assembly is coordinated. | Because BBS10 works with CCT/TRiC and BBS7 prior to mature BBSome formation, its action is placed in the assembly zone rather than in the ciliary membrane trafficking step mediated by mature BBSome-ARL6. | (pqac-00000012, pqac-00000016, pqac-00000022) |
| Pathway context | Acts in the broader **ciliary trafficking pathway** by enabling assembly of the **BBSome**, which in turn controls ciliary membrane protein composition and signaling. | The BBSome is a ciliary transport/cargo adaptor for membrane proteins and GPCRs; therefore BBS10 affects ciliary signaling **indirectly**, via assembly of this transport complex. | (pqac-00000001, pqac-00000005, pqac-00000013) |
| Downstream biology affected through BBSome | Indirectly impacts **ciliary GPCR trafficking**, **hedgehog signaling**, photoreceptor homeostasis, renal biology, and metabolic signaling because these depend on intact BBSome function. | Reviews of BBSome biology link BBSome dysfunction to receptor mislocalization, Hedgehog defects, photoreceptor degeneration, obesity, and renal abnormalities; BBS10 contributes by being required for BBSome biogenesis. | (pqac-00000000, pqac-00000001, pqac-00000013) |
| Non-ciliary/pleiotropic evidence | Emerging literature suggests BBS10 may have **additional pleiotropic roles**, but these are less established than its assembly function. | Review articles discuss roles in adipogenesis and metabolic signaling, but these are generally interpreted either as downstream consequences of BBS/ciliary dysfunction or as emerging non-ciliary functions requiring more direct validation. | (pqac-00000000, pqac-00000017, pqac-00000018) |
| Insulin signaling relevance | BBS10 has been linked to **insulin receptor-related signaling defects** in patient-derived cells. | Human mutant fibroblasts and neuronal models show impaired insulin/leptin signaling in BBS10 deficiency; this is important biologically but does not yet supersede the primary assembly role. | (pqac-00000018) |
| Disease association | **Bardet-Biedl syndrome (BBS)**; BBS10 is one of the most important human BBS genes. | BBS10 is a major contributor to molecularly diagnosed BBS and is repeatedly cited alongside BBS1 as among the most frequently mutated genes. | (pqac-00000024, pqac-00000011) |
| Contribution to mutational burden | Chaperonin-like genes **BBS6, BBS10, and BBS12 together account for >30%** of BBS mutational load; **BBS10 alone contributes ~20%** of cases in many cohorts. | Multiple reviews summarize BBS10 as a major BBS gene, with frequency varying by population. | (pqac-00000003, pqac-00000024) |
| Genotype-phenotype severity | Variants in **BBS10** are often associated with **more severe phenotypes** than variants in many core BBSome genes. | Reviews report earlier onset, greater prevalence of primary BBS features, and especially more severe renal/metabolic involvement for chaperonin-like BBS genes, including BBS10. | (pqac-00000011, pqac-00000023, pqac-00000024) |
| Variant types and recurrent alleles | Pathogenic variants include **nonsense, frameshift, missense, and truncating variants** distributed across the gene; a recurrent European allele is **p.Cys91Leufs*5**. | Reviews summarize ~100 pathogenic BBS10 variants and note population-specific recurrence patterns. Truncations affecting intermediate/equatorial domains are predicted to disrupt function strongly. | (pqac-00000019, pqac-00000024) |
| High-level expert consensus | Current expert consensus defines BBS10 as a **TCP-1/CCT-related, chaperonin-like assembly factor for the BBSome**, acting early at the basal body/pericentriolar compartment and essential for proper ciliopathy-related signaling. | This synthesis is stable across primary assembly papers and recent reviews. | (pqac-00000011, pqac-00000012, pqac-00000022) |


*Table: This table summarizes the main functional, structural, localization, interaction, and disease-related features of human BBS10. It is useful as a compact evidence map linking BBS10’s chaperonin-like TCP-1/CCT ancestry to its experimentally supported role in early BBSome assembly.*