[Yuki Nakamura & Kazue Kanehara] How 2 isozymes account for the biosynthesis of phosphatidylcholine?

The bottleneck reaction of plant phosphatidylcholine (PC) biosynthesis has long been an open question. The team led by Dr. Yuki Nakamura previously demonstrated that a pair of methyltransferase PMT1 and PMT3 is responsible for PC biosynthesis in Arabidopsis (Liu et al 2018 Plant J 96:1064-1075). However, how these two isoforms redundantly function in vivo remained unknown. Here, they showed an intriguing molecular mechanism: function of PMT3 is defined by the N-terminal leader sequence in addition to the promoter, while the PMT1 function relies solely on its promoter. Besides, they found that the immediate reaction product phosphocholine (PCho) is required for the growth of xylem, where these two PMTs show distinct expression patterns. The work was published in a British journal The Plant Journal.

Link: https://onlinelibrary.wiley.com/doi/10.1111/tpj.15741