BSPED2012 Oral Communications Oral Communications 4 (5 abstracts)
Vacuolar-type H+-ATPase V1A subunit is a molecular partner of Wolfram syndrome 1 protein, which regulates its stability and expression
Seley Gharanei , Malgorzata Zatyka , Dewi Astuti , Janine Fenton , Attila Sik , Zsuzsanna Nagy & Timothy Barrett
University of Birmingham, Birmingham, UK.
Wolfram syndrome is an autosomal recessive disorder characterised by neurodegeneration and diabetes mellitus. The gene responsible for the syndrome (WFS1) encodes an endoplasmic reticulum (ER) resident transmembrane protein, that also localises to secretory granules in pancreatic β cells. Although its precise functions are unknown, WFS1 protein deficiency affects the unfolded protein response, intracellular ion homeostasis, cell cycle progression, and granular acidification. In this study, immunofluorescent and electron-microscopy analyses confirmed that WFS1 also localizes to secretory granules in human neuroblastoma cells. We demonstrated a novel interaction between WFS1 and the V1A subunit of the vacuolar-type H+-ATPase (proton pump) by co-immunoprecipitation in HEK293 cells, and with endogenous protein in human neuroblastoma cells. We mapped the interaction to the WFS1-N terminal, but not the C-terminal domain. V1A subunit expression was reduced in WFS1 stably and transiently depleted human neuroblastoma cells and depleted NT2 cells. This reduced expression was not restored by adenoviral over-expression of BiP to correct the ER stress. Protein stability assays demonstrated that the V1A subunit was degraded more rapidly in WFS1 depleted neuroblastoma cells compared with wild type. We conclude that WFS1 has a specific interaction with the V1A subunit of H+-ATPase; this interaction may be important both for pump assembly in the ER; and for granular acidification.
Article tools
My recent searches
My recently viewed abstracts
Authors
Endocrine Abstracts
ISSN 1470-3947 (print) | ISSN 1479-6848 (online)
© Bioscientifica 2024 |
Privacy policy |
Cookie settings
BiosciAbstracts
Bioscientifica Abstracts is the gateway to a series of products that provide a permanent, citable record of abstracts for biomedical and life science conferences.
Find out more