Enhanced secretion of biologically active, non-glycosylated VEGF from Saccharomyces cerevisiae

Vascular endothelial growth factor (VEGF) mediates angiogenesis, which plays a critical role in the development and differentiation of the vascular system. VEGF is a homodimeric glycoprotein that contains one N-glycosylation site. In this study, we evaluated Saccharomyces cerevisiae expression systems producing glycosylated and non-glycosylated splice variants of human VEGF, VEGF(121), and VEGF(165). The pre region of the mating factor alpha 1 (MF alpha 1) signal sequence was found to perform better than the entire MF alpha 1 prepro signal sequence in secreting glycosylated VEGF. Secretion of non-glycosylated VEGF(165) was completely blocked, indicating the importance of glycosylation in VEGF(165) secretion. Interestingly, non-glycosylated VEGF(165) was secreted when guided by the MF alpha 1 prepro signal sequence, albeit to a lesser degree, compared to glycosylated VEGF(165). N-glycosylation in the pro region was required for the prepro sequence to promote VEGF secretion. Furthermore, substitution of asparagine at the VEGF glycosylation site with lysine or glutamic acid increased secretion of non-glycosylated VEGF, a finding not previously reported. Our findings suggest that S. cerevisiae could be a suitable host for secreting biologically active, non-glycosylated VEGF for clinical use. (c) 2013 Elsevier B.V. All rights reserved.