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Podraza-Farhanieh, A.

Publications and source records attributed to Podraza-Farhanieh, A..

2 recordsLinked to original sources

Non-overlapping requirements of ASNA-1 function for insulin secretion, cisplatin resilience, and growth revealed by genetic analysis of point mutants in C. elegans

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 ASNA-1 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 identified their importance in separating cisplatin response from its roles in insulin secretion. Further, using targeted depletion we showed asna-1 tissue requirements for C. elegans growth and development. We concluded that, targeting single residues in ASNA-1 affecting Switch I/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.

cell biology↗

Proinsulin dependent interaction between ENPL-1/GRP94 and ASNA-1 in neurons is required to maintain insulin secretion in C. elegans.

Maturation of insulin is crucial for insulin secretion and function. ENPL-1/GRP94/HSP90B1 plays an important role in this process. ASNA-1/TRC40/GET3 and ENPL-1/GRP94 are conserved insulin secretion regulators in Caenorhabditis elegans and mammals and mouse mutants display type 2 diabetes. ENPL-1 and GRP94 bind proinsulin and regulate proinsulin levels in C. elegans and cultured cells. Here we found that ASNA-1 and ENPL-1 co-operated to regulate insulin secretion in worms via a physical interaction that required pro-DAF-28/insulin but occurred independently of the insulin binding site of ENPL-1. ASNA-1 acted in neurons to promote DAF-28/insulin secretion. The interaction occurred in insulin expressing neurons and was sensitive to changes in pro-DAF-28 levels. The chaperone form of ASNA-1 is likely bound to ENPL-1. Loss of asna-1 disrupted Golgi trafficking pathways. ASNA-1 localization was affected in enpl-1 mutants and ENPL-1 overexpression partially bypassed ASNA-1 requirement. Taken together, we find a functional interaction between ENPL-1 and ASNA-1 which is necessary to maintain proper insulin secretion in C. elegans and provides insights about how their loss might produce diabetes in mammals.

cell biology↗