REGULATION OF SLO-2 BY THOC-7 THROUGH AN RNA EDITING PATHWAY

Author

Sakia Ferdousy, Southern Illinois University CarbondaleFollow

Date of Award

5-1-2024

Degree Name

Master of Science

Department

Biological Sciences

First Advisor

Zheng, Zhengui (Patrick)

Abstract

Slo2, a large conductance potassium channel in the nervous system is important for regulating neuronal function and excitability. Mutations in the gene that encodes the Slo2 channel are associated with neurological disorders, including epilepsy and intellectual disabilities in humans. However, much remains unknown about the genes and proteins that regulate Slo2 channel activity in the physiological system. This study investigates regulation of SLO-2, a homologue of mammalian Slo2 in C. elegans, by thoc-7 in an RNA editing-dependent pathway. Prior research has shown that adr-1, the gene important for RNA editing, promotes SLO-2 function by RNA editing of scyl-1 that encodes a regulator of SLO-2. To gain a better understanding of the regulation of SLO-2, this study employed a forward genetic approach to screen for mutants with a specific phenotype. Through SNP mapping and whole genome sequencing, we identified the gene thoc-7, which is predicted to be involved in mRNA export from nucleus, from the isolated mutants. The identification was further confirmed by CRISPR/Cas9-mediated gene knock-out, which showed a similar phenotype to the mutant strain. Results of electrophysiological recordings suggest that thoc-7 likely contributes to SLO-2 function in a common pathway with scyl-1. A reporter gene revealed strong expression of thoc-7 in most of the cells of C. elegans, particularly muscular and digestive system. Translational fusion with GFP showed the primary localization of the THOC-7 protein in cytoplasm, with some weak expression in the nucleus. RT-qPCR analysis suggests that thoc-7 regulates scyl-1 by through a post-transcriptional mechanism, possibly involving the transport of mRNA from cytoplasm to nucleus. This study highlights thoc-7 as a potential key regulator recruited by adr-1 to control SLO-2 via scyl-1 expression.