Chen Yee-Chun, Wu Chi-Chen, Chung Wei-Lian, Lee Fang-Jen S
Department of Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan2.
Section of Infectious Diseases, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan1.
Microbiology (Reading). 2002 Nov;148(Pt 11):3743-3754. doi: 10.1099/00221287-148-11-3743.
Secreted aspartyl proteinases (Saps) from Candida albicans are encoded by a multi-gene family and are considered to be putative virulence factors for candidiasis. SAP4-6 mRNAs were first detected during hyphae formation and were assumed to play roles in the development of disseminated candidiasis. Recombinant Sap proteins (Sap2-6) were prepared and specific antibodies were generated against Sap2-6. The presence of Sap4, Sap5 and Sap6, but not Sap2 or Sap3, was demonstrated in culture supernatants of C. albicans after induction of hyphae formation. In parallel to hyphae formation, Sap5 (approximately 40 kDa) was detected as early as approximately 6 h after induction at neutral pH, and Sap4/6 (approximately 43 kDa) were detected after approximately 24 h when the culture medium became acidic. The differential secretion of Sap5 and Sap4/6 was affected when the culture medium pH was buffered at pH 6.5 or pH 4.5. In addition, intracellular pools of Sap4-6 seem to exist, and protein is not necessary for Sap4-6 induction. This study provides the first evidence that Sap4-6 proteins in C. albicans are differentially produced and secreted during hyphae formation.
白色念珠菌分泌的天冬氨酸蛋白酶（Saps）由一个多基因家族编码，被认为是念珠菌病的假定毒力因子。SAP4 - 6 mRNA首次在菌丝形成过程中被检测到，并被认为在播散性念珠菌病的发展中起作用。制备了重组Sap蛋白（Sap2 - 6）并产生了针对Sap2 - 6的特异性抗体。在诱导菌丝形成后，白色念珠菌的培养上清液中证实存在Sap4、Sap5和Sap6，但不存在Sap2或Sap3。与菌丝形成同时，在中性pH条件下诱导后约6小时最早检测到Sap5（约40 kDa），当培养基变为酸性时，约24小时后检测到Sap4/6（约43 kDa）。当培养基pH值缓冲在pH 6.5或pH 4.5时，Sap5和Sap4/6的差异分泌受到影响。此外，似乎存在Sap4 - 6的细胞内池，并且蛋白对于Sap4 - 6的诱导不是必需的。本研究提供了首个证据，即白色念珠菌中的Sap4 - 6蛋白在菌丝形成过程中差异产生和分泌。
