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Biology subjects

Tessneer, K. L.

Publications and source records attributed to Tessneer, K. L..

3 recordsLinked to original sources

Variants in the DDX6-CXCR5 autoimmune disease risk locus influence the regulatory network in immune cells and salivary gland

Fine mapping and bioinformatic analysis of the DDX6-CXCR5 genetic risk association in Sjogrens Disease (SjD) and Systemic Lupus Erythematosus (SLE) identified five common SNPs with functional evidence in immune cell types: rs4938573, rs57494551, rs4938572, rs4936443, rs7117261. Functional interrogation of nuclear protein binding affinity, enhancer/promoter regulatory activity, and chromatin-chromatin interactions in immune, salivary gland epithelial, and kidney epithelial cells revealed cell type-specific allelic effects for all five SNPs that expanded regulation beyond effects on DDX6 and CXCR5 expression. Mapping the local chromatin regulatory network revealed several additional genes of interest, including lnc-PHLDB1-1. Collectively, functional characterization implicated the risk alleles of these SNPs as modulators of promoter and/or enhancer activities that regulate cell type-specific expression of DDX6, CXCR5, and lnc-PHLDB1-1, among others. Further, these findings emphasize the importance of exploring the functional significance of SNPs in the context of complex chromatin architecture in disease-relevant cell types and tissues.

genetics↗

Massively Parallel Reporter Assay Confirms Regulatory Potential of hQTLs and Reveals Important Variants in Lupus and Other Autoimmune Diseases

ObjectiveTo systematically characterize the potential for histone post-translational modifications, i.e., histone quantitative trait loci (hQTLs), expression QTLs (eQTLs), and variants on systemic lupus erythematosus (SLE) and autoimmune (AI) disease risk haplotypes to modulate gene expression in an allele dependent manner. MethodsWe designed a massively parallel reporter assay (MPRA) containing [~]32K variants and transfected it into an Epstein-Barr virus transformed B cell line generated from an SLE case. ResultsOur study expands our understanding of hQTLs, illustrating that epigenetic QTLs are more likely to contribute to functional mechanisms than eQTLs and other variant types, and a large proportion of hQTLs overlap transcription start sites (TSS) of noncoding RNAs. In addition, we nominate 17 variants (including 11 novel) as putative causal variants for SLE and another 14 for various other AI diseases, prioritizing these variants for future functional studies primary and immortalized B cells. ConclusionWe uncover important insights into the mechanistic relationships between genotype, epigenetics, gene expression, and SLE and AI disease phenotypes.

genomics↗

Interferon Regulatory Factor 5 (IRF5) Interacts with the Translation Initiation Complex and Promotes mRNA Translation During the Integrated Stress Response to Amino Acid Deprivation

Interferon Regulatory Factor 5 (IRF5) plays an important role in limiting pathogenic infection and tumor development. Host protection by IRF5 can occur through a variety of mechanisms including production of type I interferon and cytokines as well as the regulation of cell survival, growth, proliferation, and differentiation. While modulation of these cellular processes is attributed to IRF5 transcription factor function in the nucleus, emerging evidence suggests that IRF5 may also retain non-transcriptional regulatory properties within the cytoplasmic compartment. Consistent with this notion, we report the ability of IRF5 to control gene expression at the level of mRNA translation. Our findings demonstrate that IRF5 interacts with the translation initiation complex in the absence of the m7GTP cap-binding protein, eIF4E. We observed that under nutrient deprivation-induced cell stress, IRF5 promoted mRNA translation of the master integrated stress response (ISR) regulator, Activating Transcription Factor 4 (ATF4). Enhanced ATF4 protein expression correlated with increased levels of downstream target genes including CHOP and GADD34 and was associated with amplification of eIF2 de-phosphorylation and translational de-repression under stress. The novel mechanism we describe broadens our understanding of how IRF5 regulates gene expression and may govern diverse cellular processes in the absence of stimuli that trigger IRF5 nuclear translocation.

biochemistry↗