Cell biology analyses on the synthesis and localization of the proteins in fungal cells

1. 白色念珠菌胞内分泌性天冬氨酸蛋白酶检测的生化研究。白色念珠菌在含有牛血清白蛋白作为唯一氮源的培养基中分泌酸性蛋白酶（EPR）。用抗epr血清免疫印迹法检测了从不同膜组分中提取的细胞质组分中的43和45 kDa蛋白。45kda可能是分泌43kda蛋白的前体。2. 碱性铋染色及免疫细胞化学对蛋白酶分泌细胞超微结构的研究。我们发现在蛋白酶分泌细胞周围有许多絮状颗粒，但这些颗粒对蛋白酶分泌没有特异性。这是通过观察碱性铋染色，分泌抑制剂Brefeldin a的作用，以及使用抗epr血清的免疫电子显微镜推断出来的。3. 白色念珠菌胞外蛋白酶（EPR）诱导的生化研究。结果表明，只要有葡萄糖作为碳源，EPR在不添加氮源的情况下就能诱导，而在pH大于6.0时，无论是否有氮源，EPR都不能诱导。结果表明EPR的产生和胚管的形成在侵入过程中起着不同的作用。4. f -肌动蛋白在裂糖菌中的行为的荧光和电镜研究。(i)在蒸馏水中饥饿使位于细胞末端的肌动蛋白点分散成遍布细胞质的厚片和索。（ii）细胞松弛素A抑制隔层形成前细胞赤道肌动蛋白环的出现，细胞质囊泡和二浆体转变为致密体。肌动蛋白网络维持包括蝶状体和囊泡在内的分泌通路的组织。

1. Biochemical studies on the detection of intracellular forms of secreted aspartic proteinase in Candida albicans. C. albicans secretes acid proteinase (EPR) in the medium which contains bovine serum albumin as a sole source of nitrogen. By immunoblotting with anti-EPR serum, 43 and 45 kDa proteins were detected in the cytoplasmic fraction, which recovered from the different membrane fractions. 45 kDa would be a precursor of the secreting 43 kDa protein. 2. Ultrastructure studies on the proteinase secreting cells by alkaline bismuth staining and immunocytochemistry. We found many flocculent granules at the cell periphery of the proteinase-secreting cells, but the granules were not specific for the secretion. This was deduced from observations of alkaline bismuth staining, of effects of a secretion inhibitor Brefeldin A, and of immunoelectron microscopy using anti-EPR serum. 3. Biochemical studies on the induction of extracellular proteinase (EPR) in Candida albicans. It was shown that EPR was induced without the addition of nitrogen source so long as glucose as a carbon source is present, and not induced at a pH greater than 6.0 irrespective of the presence of nitrogen source. the results suggested EPR production and germ tube formation play different roles in the invasive process. 4. Studies on the behavior of F-actin in Schizosaccharomyces pombe by fluorescent and electron microscopy. (i) Starvation in distilled water dispersed the actin dots localized at the cell ends into thick patches and cables throughout the cytoplasm. (ii) Cytochalasin A inhibited the appearance of actin ring at a cell equator before septum formation and cytoplasmic vesicles and dictyosomes were altered in to dense bodies in the cytoplasm. Actin network maintains the organization of the secretory pathway involving dictyosomes and vesicles.