Localization and expression of phospholipases A(2) in Trimeresurus flavoviridis (habu snake) venom gland

The localization and expression profiles of phospholipases A(2) (PLA(2)s) in Trimeresurus flavoviridis venom gland were studied by means of in situ hybridization and immunohistochemical techniques. Venom gland cells are tightly arrayed in a single layer along the inlet-like lumens in which venom proteins are stored. mRNAs for PLA(2)s were detected at the high level in cytoplasm. Using the immunohistochemical technique with polyclonal anti-Asp-49-PLA(2) antibody, Asp-49-PLA(2) and, possibly, its isozymes were detected in intracellular granules and in venom lumens. The intracellular granules containing PLA(2) proteins appear to be transferred from the nucleus towards the outer membrane facing the lumen, and then to be secreted.