The Arabidopsis TSPO-related protein is a stress and abscisic acid-regulated, ER-Golgi-localized membrane protein
(2009) The Plant Journal — Vol. 60, n° 2, p. 242-256 (2009)
Files
No attached file found for this publication.
Details
- Authors
- Abstract
- Summary The Arabidopsis gene At2g47770 encodes a membrane-bound protein designated AtTSPO (Arabidopsis thaliana TSPO-related). AtTSPO is related to the bacterial outer membrane tryptophan-rich sensory protein (TspO) and the mammalian mitochondrial 18 kDa Translocator Protein (18 kDa TSPO), members of the TspO/MBR domain-containing membrane proteins. In this study we showed that AtTSPO is mainly detected in dry seeds, but can be induced in vegetative tissues by osmotic or salt stress or abscisic acid treatment, corroborating available transcriptome data. Using subcellular fractionation, immunocytochemistry, and fluorescent protein tagging approaches we present evidence that AtTSPO is targeted to the secretory pathway in plant. Induced or constitutively expressed AtTSPO can be detected in the endoplasmic reticulum and the Golgi stacks of plant cell. AtTSPO tagged with fluorescent protein in transgenic plant (Arabidopsis and tobacco) was mainly detected in Golgi stacks of leaf epidermal cells. Constitutive expression of AtTSPO resulted in increased sensitivity to NaCl, but not to osmotic stress, and in reduced greening of cultured Arabidopsis cells under light growing conditions. Transgenic Arabidopsis plants overexpressing AtTSPO were more sensitive to ABA-induced growth inhibition, indicating that constitutive expression of AtTSPO may enhance ABA sensitivity. AtTSPO is rapidly downregulated during seeds imbibition, and the ABA-dependent induction in plant is transient. Downregulation of AtTSPO seems to be boosted by aminolevulenic acid treatment. Taken together, these results suggest that AtTSPO is a highly regulated protein, induced by abiotic stress to modulate, at least in part, transient intracellular ABA-dependent stress perception and/or signalling.
- Affiliations
Citations
Guillaumot, D., Guillon, S., Deplanque, T., Vanhee, C., Gumy, C., Masquelier, D., Morsomme, P., & Batoko, H. (2009). The Arabidopsis TSPO-related protein is a stress and abscisic acid-regulated, ER-Golgi-localized membrane protein. The Plant Journal, 60(2), 242-256. https://doi.org/10.1111/j.1365-313X.2009.03950.x (Original work published 2009)