[show abstract][hide abstract] ABSTRACT: The evolutionarily conserved cohesin complex was originally described for its role in regulating sister-chromatid cohesion during mitosis and meiosis. Cohesin and its regulatory proteins have been implicated in several human developmental disorders, including Cornelia de Lange (CdLS) and Roberts syndromes. Here we show that human mutations in the integral cohesin structural protein RAD21 result in a congenital phenotype consistent with a "cohesinopathy." Children with RAD21 mutations display growth retardation, minor skeletal anomalies, and facial features that overlap findings in individuals with CdLS. Notably, unlike children with mutations in NIPBL, SMC1A, or SMC3, these individuals have much milder cognitive impairment than those with classical CdLS. Mechanistically, these mutations act at the RAD21 interface with the other cohesin proteins STAG2 and SMC1A, impair cellular DNA damage response, and disrupt transcription in a zebrafish model. Our data suggest that, compared to loss-of-function mutations, dominant missense mutations result in more severe functional defects and cause worse structural and cognitive clinical findings. These results underscore the essential role of RAD21 in eukaryotes and emphasize the need for further understanding of the role of cohesin in human development.
The American Journal of Human Genetics 05/2012; 90(6):1014-27. · 11.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cornelia de Lange Syndrome (CdLS) is a rare congenital malformation disorder. About half of the patients with CdLS carry mutations in the NIPBL gene encoding the NIPBL protein, a subunit of the Cohesin loading complex. Recent studies show association of Cohesin with chromatin-remodeling complexes, either by establishing cohesion or by recruiting Cohesin to specific chromosome locations. In yeast two-hybrid assays, we identified an interaction of NIPBL with the histone deacetylases -1 and -3. These interactions were confirmed in mammalian cells by coimmunoprecipitation and a critical region for interaction was defined to a stretch of 163 amino acids of a highly conserved region of NIPBL, which is mutated in patients with CdLS. Utilizing reporter gene assays, we could show that NIPBL fused to the GAL4-DNA-binding domain (GAL4-DBD) represses promoter activity via the recruitment of histone deacetylases. Interestingly, this effect is dramatically reduced by both NIPBL missense mutations identified in CdLS and by chemical inhibition of the histone deacetylases. Our data are the first to indicate a molecular and functional connection of NIPBL with chromatin-remodeling processes via the direct interaction with histone deacetylases.
Nucleic Acids Research 11/2008; 36(20):6450-8. · 8.28 Impact Factor