A392V and R945X mutations cause orofacial clefts via impairing PTCH1 function.

The Hedgehog (HH) signaling plays key roles in embryogenesis and organogenesis, and its dysfunction causes a variety of human birth defects. Orofacial cleft (OFC) is one of the most common congenital craniofacial defects, and its etiology is closely related to mutations in multiple components in the HH pathway, including the PTCH1 receptor. A quantity of PTCH1 variants have been associated with OFC, but the pathogenicity and underlying mechanism of these variants have not been functionally validated. In our previous studies, we identified two PTCH1 variants (A392V and R945X) in two families with hereditary OFC. Here we explore the functional consequences of these two variants. In zebrafish embryos, microinjection of wild type PTCH1 mRNA causes curved body axis and craniofacial anomalies. In contrast, microinjection of A392V and R945X PTCH1 mRNAs results in much milder phenotypes, suggesting these two variants are loss-of-function mutations. In mammalian cells, A392V and R945X mutations reverse the inhibitory effect of PTCH1 on HH signaling. Biochemically, the two mutants PTCH1 show lower expression levels and shortened half-life, indicting these mutations decrease the stability of PTCH1. A392V and R945X mutations also appear to cause PTCH1 to localize away from vesicles. Taken together, our findings indicate that A392V and R945X variants are loss-of-function mutations that disrupt the function of PTCH1 and thus cause dysregulation of HH signaling, leading to the pathogenesis of OFC. Copyright © 2022. Published by Elsevier Inc.

Citation

Qing He, Xingke Hao, Shanying Bao, Xiantao Wu, Linping Xu, Yuxia Hou, Yingjia Huang, Leiyuan Peng, Huimei Huang, Yi Ding, Huaxiang Zhao. A392V and R945X mutations cause orofacial clefts via impairing PTCH1 function. Genomics. 2022 Nov;114(6):110507

Mesh Tags

Substances

PMID: 36265746

search → result