The Role of Rare Coding Variants in Parkinson's Disease GWAS Loci
FRONTIERS IN NEUROLOGY
Authors: Germer, Elisaebeth Luisa; Imhoff, Sophie; Vilarino-Guell, Carles; Kasten, Meike; Seibler, Philip; Bueggemann, Norbert; Klein, Christine; Trinh, Joanne
Abstract
Introduction: Genome-wide association studies (GWAS) have identified multiple loci associated with Parkinson's disease (PD) risk. The presence of rare variants within these loci that may account for the increased susceptibility requires further investigation. Methods: Using exome sequencing, we performed a comprehensive rare variant screen of genes located within 56 novel PD loci. We first analyzed exomes from 109 subjects in the discovery cohort (85 diagnosed with PD and 24 healthy controls) and filtered for rare coding variants with minor allele frequency 15. Further investigation of exome data from a replication cohort of 2,859 European patients with PD (International Parkinson's Disease Genomics Consortium) and 24,146 non-Finnish European controls from gnomAD were used for association testing of specific rare variants found in the discovery cohort. Results: Our genetic screening identified 54 potential disease-relevant variants in 71 genes in 109 subjects. Six out of 54 variants were found in two or more patients and were not observed in healthy controls: DNAH1 p.A3639T, STAB1 p.S1089G, ANK2 p.V3634D, ANK2 p.R3906W, SH3GL2 p.G276V, and NOD2 p.G908R. Replication in the International Parkinson's Disease Genomics Consortium (IPDGC) confirmed the association with PD risk for three out of the six identified variants (STAB1 p.S1089G, SH3GL2 p.G276V, and NOD2 p.G908R) (p < 10(-3)). Conclusion: Our study suggests that some of the associations identified in PD risk loci can be ascribed to rare variants with likely functional effects that modify PD risk.
Tetramerization of SATB1 is essential for regulating of gene expression
MOLECULAR AND CELLULAR BIOCHEMISTRY
Authors: Zheng, Minying; Xing, Wancai; Liu, Yabing; Li, Meng; Zhou, Hao
Abstract
Special AT-rich sequence-binding protein 1 (SATB1) functions as a 'genome organizer' in tumorigenesis. Our previous report showed that SATB1 forms a tetramer through its N-terminal ubiquitin like domain rather than the proposed PDZ domain. In the present study, we aim to illustrate whether this oligomerization is critical to its function as a global repressor of gene expression in vivo. Luciferase and GST pull-down assays demonstrated that disrupting SATB1's tetramerization not only affects the activities of promoters but also influences the recruitment of interaction partners. Furthermore, we developed stable cell lines that overexpressed either the SATB1 tetramer or STAB1 dimer (KWN-AAA) and monitored global gene expression. Gene expression profiling revealed that over 1000 genes were significantly upregulated or downregulated upon the overexpression of SATB1 or the SATB1 (KWN-AAA) mutant. These data implied that SATB1 might regulate gene expression through its different oligomerization state. In conclusion, we inferred that the oligomerization of SATB1 is pivotal to its function of different biological processes.