A temperature-sensitive mutation in the Arabidopsis thaliana phosphomannomutase gene disrupts protein glycosylation and triggers cell death

作者：Hoeberichts Frank A; Vaeck Elke; Kiddle Guy; Coppens Emmy; van de Cotte Brigitte; Adamantidis Antoine; Ormenese Sandra; Foyer Christine H; Zabeau Marc; Inze Dirk; Perilleux Claire; Van Breusegem Frank^*; Vuylsteke Marnik

来源：Journal of Biological Chemistry, 2008, 283(9): 5708-5718.

Eukaryotic phosphomannomutases (PMMs) catalyze the interconversion of mannose 6-phosphate to mannose 1-phosphate and are essential to the biosynthesis of GDP-mannose. As such, plant PMMs are involved in ascorbic acid (AsA) biosynthesis and N-glycosylation. We report on the conditional phenotype of the temperature-sensitive Arabidopsis thaliana pmm- 12 mutant. Mutant seedlings were phenotypically similar to wild type seedlings when grown at 16 - 18 degrees C but died within several days after transfer to 28 degrees C. This phenotype was observed throughout both vegetative and reproductive development. Protein extracts derived from pmm-12 plants had lower PMM protein and enzyme activity levels. In vitro biochemical analysis of recombinant proteins showed that the mutant PMM protein was compromised in its catalytic efficiency (K-cat/K-m). Despite significantly decreased AsA levels in pmm-12 plants, AsA deficiency could not account for the observed phenotype. Since, at restrictive temperature, total glycoprotein patterns were altered and glycosylation of protein-disulfide isomerase was perturbed, we propose that a deficiency in protein glycosylation is responsible for the observed cell death phenotype.

• 出版日期2008-2-29