Use of GFP (Green Fluorescent Protein) for monitoring annexin 1 function in phagocytosis

Annexin 1 belongs to a family of proteins that bind negatively charged phospholipids and membranes in a calcium dependent manner. Most of the proposed functions concern processes involving membrane fusion and/or fission such as that involved in phagocytosis. Latex beads were used in this study. cDNA of wild-type annexin 1 was expressed by transfection as a fusioned protein to GFP (green flourescent protein) at its N- terminal end. It turned out that, despite the regulatory importance of the N- terminal domain, the overexpression and the fusion of annexin 1 to GFP did not significantly alter the phagosome colocalization and this protein remained associated with the phagosomal protein complex during the maturation process. As GFP is becoming an important reporter molecule for monitoring gene expresion and protein localization in vivo, in situ and in real time, the significance of this finding on the physiological function of annexin 1 will be discussed. Keywords: annexin 1 â GFP â J-774A 1â phagocytosis â protein expression