Identification of C. elegans ASNA-1 domains and tissue requirements that differentially influence platinum sensitivity and growth control

Abstract

ASNA1 plays an essential role in cisplatin chemotherapy response, type 2 diabetes, and heart disease. It is also an important biomarker in the treatment response of many diseases. Biochemically, ASNA1 has two mutually exclusive redox-modulated roles: a tail-anchored protein (TAP) targeting function in the reduced state and a holdase/chaperone function in the oxidized state. Assigning biochemical roles of mammalian ASNA1 to biomedical functions is crucial for successful therapy development. Our previous work showed the relevance of the C. elegans ASNA-1 homolog in modeling cisplatin response and insulin secretion. Here we analyzed two-point mutants in highly conserved residues in C. elegans ASNA-1 and determined their importance in separating the cisplatin response function from its roles in insulin secretion. asna-1(ΔHis164) and asna-1(A63V) point mutants, which both preferentially exist in the oxidized state, displayed cisplatin sensitivity phenotype as well as TAP insertion defect but not an insulin secretion defect. Further, using targeted depletion we analyzed the tissue requirements of asna-1 for C. elegans growth and development. Somatic depletion of ASNA-1 as well as simultaneous depletion of ASNA-1 in neurons and intestines resulted in an L1 arrest. We concluded that, targeting single residues in ASNA-1 affecting Switch I/Switch II domain function, in comparison to complete knockdown counteracted cisplatin resistance without jeopardizing other important biological functions. Taken together, our study shows that effects on health caused by ASNA1 mutations can have different biochemical bases.

A proinsulin-dependent interaction between ENPL-1 and ASNA-1 in neurons is required to maintain insulin secretion in C. elegans

“…It has been shown that C. elegans ASNA-1 and its yeast homolog GET3 can work as ATPase-dependent targeting proteins. However, under the high oxidative stress condition, the proteins undergo an oxidation-dependent conformational change and are converted into an ATPase-independent chaperone ( Raj et al, 2021 , 2022 ; Voth et al, 2014 ).…”

Cisplatin toxicity is counteracted by the activation of the p38/ATF-7 signaling pathway in post-mitotic C. elegans

“…Our previous work has demonstrated in worms that there is an increase in ROS levels when C. elegans 1-day-old adults are subjected to cisplatin treatment. This consequently led to higher levels of oxidized ASNA-1 and disturbances in ER-targeted tail-anchored membrane protein insertion 9 , 51 . In this study, we started by asking to what extent ROS detoxification was essential for survival.…”