Page 4 - F. Cell biology

[F. Cell biology-2]

Tubby like protein family is an adaptor for ciliary G protein-

coupled receptor trafficking

Kyoungeun Kim¹˙¹, Seok Jun Moon¹

¹Oral Biology, Yonsei University College of Dentistry, Seoul 03722, Korea, south

Cilia are highly specialized antennae-like cellular organelles. An elaborate mechanism for establishing and
maintaining the compartmentalization of cilia is necessary for proper ciliary function, which includes the entry,
localization, and exit of specific signaling molecules to and from the ciliary compartment. Tubby and Tulp3 are

adapters for the ciliary trafficking of G protein-coupled receptors (GPCRs). Since Tubby like protein family (TULP)

shares N-terminal IFT binding domain and C-terminal Tubby domain, it is intriguing to speculate that all TULPs
function as adaptors for ciliary membrane cargo trafficking. Here we investigated whether TULPs regulate ciliary
protein trafficking. Using hTERT RPE-1(RPE1) cells, we demonstrate TULPs show functional redundancy in ciliary

GPCR trafficking. However, hypothalamic single-cell RNA-seq analysis reveals that Tubby and Tulp3 are expressed
mutually exclusive, suggesting that these two TULPs are tissue-specific functions. Finally, we confirmed that ciliary

GPCR trafficking impairs in the hypothalamus of Tubby mice. Our data indicate that TULPs share similar functions
but also have functional diversity through its differential tissue distribution.