Open AccessBiosynthesis of glycoproteins in the pathogenic fungus Candida albicans : Activation of dolichol phosphate mannose synthase by cAMP‐mediated protein phosphorylation
Author(s) -
ArroyoFlores Blanca L.,
CalvoMéndez Carlos,
FloresCarreón Arturo,
LópezRomero Everardo
Publication year - 2005
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1016/j.femsim.2005.05.016
Subject(s) - dolichol , dephosphorylation , biochemistry , phosphorylation , mannose , biology , enzyme , phosphatase , atp synthase , candida albicans , biosynthesis , protein phosphorylation , protein kinase a , microbiology and biotechnology
Following incubation with ATP and a cAMP‐dependent protein kinase under optimal conditions of lipid acceptor, phospholipid and metal ion requirements, the transfer activity of partially purified dolichol phosphate mannose synthase (DPMS) increased about 60% and this activation correlated with a 50% increase in V max with no alteration in the apparent K m for GDP‐Manose. Phosphorylation with [γ‐ 32 P]ATP resulted in the labeling of several polypeptides, one of which exhibited the molecular weight of the enzyme (30 kDa) and was also recognized using a specific anti‐DPMS monoclonal antibody. This and the fact that the phosphate label could be removed by an alkaline phosphatase indicate that Candida DPMS may be regulated by phosphorylation–dephosphorylation, a mechanism that has been proposed for the enzyme in other organisms.