TLDR Hairless protein can both repress and activate vitamin D receptor functions, affecting gene regulation.
The study investigated the role of Hairless (HR) as a coregulator of the vitamin D receptor (VDR) and its impact on VDR activation by 1α,25-dihydroxyvitamin D(3) and lithocholic acid (LCA). HR was found to repress VDR transactivation induced by both ligands and also affected VDR mutants involved in retinoid X receptor (RXR) heterodimer communication. HR enhanced the association of VDR with a corepressor, indicating its role in VDR-RXR allosteric communication and corepressor complex formation. HR knockdown in keratinocyte-derived cells showed that HR acts as both a corepressor and coactivator, influencing gene-selective transcription regulation.
53 citations,
May 2010 in “Journal of Cellular Physiology” Mice without Vitamin D receptors have hair growth problems because of issues in the hedgehog signaling pathway.
76 citations,
January 2010 in “Journal of bone and mineral metabolism” [object Object] 
42 citations,
July 2007 in “Journal of Biological Chemistry” Most Hairless gene mutations reduce its ability to work with the Vitamin D Receptor, which might explain a certain type of hair loss.
78 citations,
November 2005 in “Endocrinology” Hairless protein can block vitamin D activation in skin cells.
1308 citations,
March 1998 in “Journal of bone and mineral research” The vitamin D receptor is crucial for bone health and affects various body systems, with mutations potentially leading to disease.
62 citations,
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March 2014 in “BoneKEy Reports” Mutations in the vitamin D receptor cause hereditary vitamin D-resistant rickets, leading to poor bone health and requiring high calcium doses for treatment.
[object Object] 151 citations,
June 2010 in “Endocrinology and metabolism clinics of North America” Two rare genetic diseases cause severe rickets in children due to defects in vitamin D metabolism.
78 citations,
November 2005 in “Endocrinology” Hairless protein can block vitamin D activation in skin cells.
