23 janvier 2018
Ce document est lié à :
http://archipel.uqam.ca/12094/
Ce document est lié à :
http://dx.doi.org/10.1073/pnas.1715378115
Ce document est lié à :
doi:10.1073/pnas.1715378115
Catherine Bélanger et al., « Dysregulation of cotranscriptional alternative splicing underlies CHARGE syndrome », UQAM Archipel : articles scientifiques, ID : 10670/1.qznz2l
CHARGE syndrome—which stands for coloboma of the eye, heart defects, atresia of choanae, retardation of growth/development, genital abnormalities, and ear anomalies—is a severe developmental disorder with wide phenotypic variability, caused mainly by mutations in CHD7 (chromodomain helicase DNA-binding protein 7), known to encode a chromatin remodeler. The genetic lesions responsible for CHD7 mutation-negative cases are unknown, at least in part because the pathogenic mechanisms underlying CHARGE syndrome remain poorly defined. Here, we report the characterization of a mouse model for CHD7 mutation-negative cases of CHARGE syndrome generated by insertional mutagenesis of Fam172a (family with sequence similarity 172, member A). We show that Fam172a plays a key role in the regulation of cotranscriptional alternative splicing, notably by interacting with Ago2 (Argonaute-2) and Chd7. Validation studies in a human cohort allow us to propose that dysregulation of cotranscriptional alternative splicing is a unifying pathogenic mechanism for both CHD7 mutation-positive and CHD7 mutation-negative cases. We also present evidence that such splicing defects can be corrected in vitro by acute rapamycin treatment.