Hyaluronan Synthesis in Cultured Tobacco Cells (BY-2) Expressing a Chlorovirus Enzyme: Cytological Studies

Extraction of hyaluronan from animals or mi- crobial 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 (proto- plasts, 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 suc- cessfully functions on the vacuolar membrane and synthe- sizes/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.