Journal of Microbiology

Ultrastructural studies of encystment in allomyces macrogynus: Kim, Jung Soeup , Youn, Hyun Joo , Cho, Chung Won; J. Microbiol. 1996;34(3):220-224.

Abstract: Ultrastructural organization of encysting zoospores of Allomyces macrogynus was examined using the methods of cryofixation and freeze substitution. During enxystment, obvious changes were observed at the surface of the plasma membrane and in the structure of gamma particles. Many multivesicular bodies associated with the plasma membrane were observed at early stages of encystment. After induction of encystment, vesicles were found within the gamma particles. These vesicles appeared to leave gamma particles after formaing multivesicular bodies. This study suggests that the cell wall formation during encystment is mediated by the fusion of multivesicular bodies with the plasma membrane.

Stage-specific change and regulation of endogenous protein phosphorylation in allomyces macrogynus: Park, Young Shik , Oh, Keun Hee , Lee, Soo Woong , Seong, Chang Soo , Park, I Ha , Yim, Jeong Bin; J. Microbiol. 1996;34(4):374-378.

Abstract: In the aquatic fungus Allomyces macrogynus the effects of Ca^2+ and cAMP on the intracellular signal transduction of zeoospore germination were studied using in vitro protein phosphorylation assay system. An endogenuously phosphorylated protein (p50) having molecular weight of 50 kDa on SDS-PAGE was found in soluble fractions of both zeoospore and mycelium. In zoospore extract, the endogenous phophorylation of p50 was weak without any effectors, but was enhanced by Ca^2+ and even more by cAMP. Phosphorylation of the same protein in mycelial extract was high only in the absence of cAMP. Irrespective of the presence of Ca^2+ and cAMP, its phosphorylation was antagonistically suppressed in assay of combined zoospore and mycelial extracts. These results suggest that p50 is interconvertible in phosphorylation/dephosphorylation as a novel protein involved in germination of A. macrogynus. The antagonistic effect of cAMP to the phosphorylation of p50s from different developmental stages may be important in the regulation of cellular differentiation.

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