Disease relevance of pmgA

• A novel gene, pmgA, specifically regulates photosystem stoichiometry in the cyanobacterium Synechocystis species PCC 6803 in response to high light [1].
• Interestingly, insertional inactivation of the pmgA gene, which encodes a putative serine-threonine kinase similar to RsbW and RsbT in Bacillus subtilis, results in a similar increase in glycogen and Glc-induced lethality [2].

High impact information on pmgA

• Based on these results, we propose that alpha-tocopherol plays a nonantioxidant regulatory role in photosynthesis and macronutrient homeostasis through a signal transduction pathway that also involves PmgA [2].
• To gain insight into the role of pmgA, we investigated the mutant phenotype of pmgA in detail [1].
• Finally, early induction of pmgA expression detected by reverse transcriptase-PCR upon the shift to HL led us to conclude that pmgA is the first gene identified, to our knowledge, as a specific regulatory factor for HL acclimation [1].
• Repression of the promoter activity of the psaA gene by a pmgA-dependent mechanism was shown to be essential for the adjustment of photosystem stoichiometry under HL conditions [3].

Biological context of pmgA

• When gene expression profiles of wild-type cells and a pmgA-disrupted mutant that cannot modulate photosystem stoichiometry under HL were compared, a large increase in the psaAB and psaA transcript levels was observed in the mutant under prolonged exposure to HL for 6 h [3].

References