Hyaluronan synthesis in cultured tobacco cells (BY-2) expressing a chlorovirus enzyme: Cytological studies

Extraction of hyaluronan from animals or microbial fermentation has risks including contamination with pathogens and microbial toxins. In this work, tobacco cultured‐cells (BY‐2) were successfully transformed with a chloroviral hyaluronan synthase (cvHAS) gene to produce hyaluronan. Cytological studies revealed accumulation of HA on the cells, and also in subcellular fractions (protoplasts, miniplasts, vacuoplasts, and vacuoles). Transgenic BY‐2 cells harboring a vSPO‐cvHAS construct containing the vacuolar targeting signal of sporamin connected to the N‐terminus of cvHAS accumulated significant amounts of HA in vacuoles. These results suggested that cvHAS successfully functions on the vacuolar membrane and synthesizes/transports HA into vacuoles. Efficient synthesis of HA using this system provides a new method for practical production of HA. Biotechnol. Bioeng. 2013; 110: 1174–1179. © 2012 Wiley Periodicals, Inc. In this study, the authors describe the novel production of HA in cultured tobacco cells (BY‐2). The tobacco cells were successfully transformed with the chloroviral hyaluronan synthase (cv‐has) gene with or without a vacuolar targeting signal. The results showed that the sporamin vacuolar targeting signal (vSPO) operated well in BY‐2 cells, targeting the cvHAS protein to the vacuolar membrane where HA was synthesized and transported into the storage vacuole.