| Aspect | Key points | Best supporting sources (with year and DOI/URL) |
|---|---|---|
| Identity / domains | INTU in the retrieved literature matches human **Inturned planar cell polarity effector** (UniProt Q9ULD6), a CPLANE-associated PCP effector. Structural work supports an **N-terminal PDZ domain** plus **multiple longin-like domains (LD1-LD3)** that organize CPLANE assembly and membrane interactions. (pqac-00000001, pqac-00000002, pqac-00000004) | **Langousis et al., 2022**, *Science Advances*, doi:10.1126/sciadv.abn0832, https://doi.org/10.1126/sciadv.abn0832; **Martín-Salazar & Valverde, 2022**, *Biomolecules*, doi:10.3390/biom12060847, https://doi.org/10.3390/biom12060847 |
| Complex membership | INTU is a **core CPLANE subunit** with **WDPCP and FUZ**; it also associates with **JBTS17/C5orf42** and **RSG1**. Tandem affinity purification/co-IP datasets identified INTU within a broader ciliogenesis network and linked it to **IFT-A proteins**. (pqac-00000003, pqac-00000004, pqac-00000005) | **Toriyama et al., 2016**, *Nature Genetics*, doi:10.1038/ng.3558, https://doi.org/10.1038/ng.3558; **Martín-Salazar & Valverde, 2022**, https://doi.org/10.3390/biom12060847 |
| Molecular function | INTU is not an enzyme of classical metabolism; its primary function is as a **ciliogenesis scaffold/effector** that helps organize CPLANE and **promote basal-body recruitment/assembly of IFT-A machinery**. Structural/biochemical studies also support that **INTU-FUZ acts as a Rab23 guanine-nucleotide exchange factor (GEF)**, and CPLANE shows **phosphoinositide binding**, especially **PI(3)P**. (pqac-00000001, pqac-00000002, pqac-00000003, pqac-00000006) | **Langousis et al., 2022**, https://doi.org/10.1126/sciadv.abn0832; **Toriyama et al., 2016**, https://doi.org/10.1038/ng.3558 |
| Localization | Experimental imaging in multiciliated cells showed **GFP-Inturned localizes to basal bodies**; JBTS17 knockdown alters basal-body GFP-Inturned signal. Structural interpretation further suggests CPLANE/INTU acts on **PI(3)P-rich vesicles near the nascent ciliary vesicle/base of cilia**, rather than as an axonemal transport particle. (pqac-00000003, pqac-00000008, pqac-00000009, pqac-00000010, pqac-00000011, pqac-00000001) | **Toriyama et al., 2016** (Supplementary Fig. 4c, Supp. Fig. 6), https://doi.org/10.1038/ng.3558; **Langousis et al., 2022**, https://doi.org/10.1126/sciadv.abn0832 |
| Pathways | INTU connects **planar cell polarity (PCP)** to **ciliogenesis**, **IFT-A-dependent ciliary trafficking**, and downstream **Hedgehog (Hh) signaling**. Reviews emphasize that CPLANE defects impair cilium formation and Hh pathway activation; mechanistic papers place INTU in late ciliogenesis and IFT recruitment. (pqac-00000000, pqac-00000003, pqac-00000005, pqac-00000006, pqac-00000007) | **Toriyama et al., 2016**, https://doi.org/10.1038/ng.3558; **Martín-Salazar & Valverde, 2022**, https://doi.org/10.3390/biom12060847; **Leggere, 2023**, doi:10.26153/tsw/50147, https://doi.org/10.26153/tsw/50147 |
| Disease variants / phenotypes | Human **INTU variants** reported in ciliopathy contexts include **Ala452Thr (A452; nephronophthisis)**, **Glu500Ala (E500; short-rib polydactyly)**, **Asn132Lysfs*11**, and **Gln276Ter**. Reported phenotypes include **orofaciodigital syndrome**, **short-rib polydactyly**, and **nephronophthisis**; one OFD case showed **Y-shaped metacarpals**, and an SRP case was transheterozygous for **INTU and WDR35** variants. (pqac-00000003, pqac-00000008, pqac-00000009, pqac-00000010, pqac-00000011) | **Toriyama et al., 2016**, https://doi.org/10.1038/ng.3558 |
| Key recent developments (2023-2024) | Recent work did not add many INTU-specific primary studies in the retrieved set, but 2023-2024 sources strengthened the **CPLANE framework**: reviews highlighted INTU/FUZ/WDPCP in ciliopathies and PCP-cilia crosstalk; actin-focused 2024 work on **FUZ** showed CPLANE can regulate **basal-body actin/RhoA**, likely relevant to INTU-containing complexes; 2023 proteomics/reviews continued to place INTU as an important PCP/ciliogenesis regulator. Important remaining gap: reviews note that the **specific INTU role within IFT regulation remains incompletely resolved**. (pqac-00000012, pqac-00000014, pqac-00000015, pqac-00000000) | **Kalot et al., 2024**, *Frontiers in Nephrology*, doi:10.3389/fneph.2023.1331847, https://doi.org/10.3389/fneph.2023.1331847; **Sharma et al., 2024**, *Development*, doi:10.1242/dev.202322, https://doi.org/10.1242/dev.202322; **Leggere, 2023**, https://doi.org/10.26153/tsw/50147 |


*Table: This table condenses the best-supported functional annotation for human INTU/Q9ULD6, covering identity, mechanism, localization, pathways, disease links, and recent developments. It is useful as a quick evidence-based reference for report drafting.*