The RAIG Family Member, GPRC5D, Is Associated With Hard-Keratinized Structures

The study identified GPRC5D, a member of the RAIG1 family of G-protein coupled receptors, as being uniquely expressed in hard-keratinized structures such as hair follicles and nails. GPRC5D expression was observed during specific phases of the hair cycle and was induced by all-trans retinoic acid (ATRA). Overexpression of GPRC5D in cultured cells altered the expression of hair keratin genes, suggesting its role in hair follicle differentiation and keratin synthesis. The findings indicated that GPRC5D might be crucial for the regulation of hard keratin genes and provided insights into the molecular mechanisms underlying hair growth and maintenance.