Novel subcellular locations and functions for secretory pathway Ca2+/Mn2+-ATPases

Southall, T. D., Terhzaz, S. , Cabrero, P. , Chintapalli, V. R., Evans, J. M., Dow, J. A.T. and Davies, S.-A. (2006) Novel subcellular locations and functions for secretory pathway Ca2+/Mn2+-ATPases. Physiological Genomics, 26(1), pp. 35-45. (doi: 10.1152/physiolgenomics.00038.2006) (PMID:16609144)

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Secretory pathway Ca2+/Mn2+-ATPases (SPCAs) are important for maintenance of cellular Ca2+ and Mn2+ homeostasis, and, to date, all SPCAs have been found to localize to the Golgi apparatus. The single Drosophila SPCA gene (SPoCk) was identified by an in silico screen for novel Ca2+-ATPases. It encoded three SPoCk isoforms with novel, distinct subcellular specificities in the endoplasmic reticulum (ER) and peroxisomes in addition to the Golgi. Furthermore, expression of the peroxisome-associated SPoCk isoform was sexually dimorphic. Overexpression of organelle-specific SPoCk isoforms impacted on cytosolic Ca2+ handling in both cultured Drosophila cells and a transporting epithelium, the Drosophila Malpighian (renal) tubule. Specifically, the ER isoform impacted on inositol (1,4,5)-trisphosphate-mediated Ca2+ signaling and the Golgi isoform impacted on diuresis, whereas the peroxisome isoform colocalized with Ca2+ “spherites” and impacted on calcium storage and transport. Interfering RNA directed against the common exons of the three SPoCk isoforms resulted in aberrant Ca2+ signaling and abolished neuropeptide-stimulated diuresis by the tubule. SPoCk thus contributed to both of the contrasting requirements for Ca2+ in transporting epithelia: to transport or store Ca2+ in bulk without compromising its use as a signal.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Cabrero, Mr Pablo and Dow, Professor Julian and Terhzaz, Dr Selim and Davies, Professor Shireen and Chintapalli, Dr Venkateswara
Authors: Southall, T. D., Terhzaz, S., Cabrero, P., Chintapalli, V. R., Evans, J. M., Dow, J. A.T., and Davies, S.-A.
College/School:College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Virus Research
Journal Name:Physiological Genomics
ISSN (Online):1531-2267
Published Online:11 April 2006

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
337031Function of intracellular calcium pools in renal transport - unravelling complexities using targeted calcium reportersShireen DaviesBiotechnology and Biological Sciences Research Council (BBSRC)S18917Institute of Molecular Cell and Systems Biology