Serum Albumin Stimulates Protein Kinase G-dependent Microneme Secretion in Toxoplasma gondii.

ABSTRACT: Microneme secretion is essential for motility, invasion, and egress in apicomplexan parasites. Although previous studies indicate that Ca(2+) and cGMP control microneme secretion, little is known about how these pathways are naturally activated. Here we have developed genetically encoded indicators for Ca(2+) and microneme secretion to better define the signaling pathways that regulate these processes in Toxoplasma gondii We found that microneme secretion was triggered in vitro by exposure to a single host protein, serum albumin. The natural agonist serum albumin induced microneme secretion in a protein kinase G-dependent manner that correlated with increased cGMP levels. Surprisingly, serum albumin acted independently of elevated Ca(2+) and yet it was augmented by artificial agonists that

SUBMITTER: Brown KM 

PROVIDER: S-EPMC4850294 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature