ABSTRACT
Candida glabrata is an emerging opportunistic pathogen that has intrinsic resistance to azoles. During infection or while living as a commensal, it encounters nutritional stresses such as deficiency of carbon or nitrogen sources. Herein, we investigate the expression and activity of PrA, Ape1, Ape3 and CpY vacuolar proteases during these stressful nutrimental conditions. Our findings demonstrate a differential activity profile depending on the addition or lack of carbon, nitrogen or both. Of the four proteases tested, PrA and Ape3 showed a higher activity in the absence of nitrogen. Steady-state RNA levels for all the proteases were also differentially expressed although not always correlated with its activity, suggesting multiple levels of regulation. Microscopy observations of C. glabrata cells subjected to the different conditions showed an increase in the vacuolar volume. Moreover, the presence of ATG8-PE and an increased expression of ATG8 were observed in the yeast under the tested conditions suggesting that C. glabrata is in autophagy stage. Taken together, our results showed that PrA, Ape1, Ape3 and CpY have varying activities and expression depending on whether nitrogen or carbon is added to the media, and that these vacuolar proteases might have a role in the autophagy process.
Subject(s)
Candida glabrata/genetics , Candida glabrata/metabolism , Gene Expression Regulation, Fungal , Peptide Hydrolases/genetics , Peptide Hydrolases/metabolism , Vacuoles/enzymology , Vacuoles/genetics , Amino Acid Sequence , Autophagy , Binding Sites , Computational Biology/methods , Enzyme Activation , Fungal Proteins/chemistry , Fungal Proteins/genetics , Fungal Proteins/metabolism , Promoter Regions, Genetic , Protein Binding , Transcription Factors/metabolismABSTRACT
Los tumores estromales forman parte, junto con leiomiomas y schwanomas, de los denominados tumores mesenquimatosos de la pared intestinal. El tumor estromal se diferencia histológicamente de los demás tumores mesenquimatosos al derivar de las células intersticiales de Cajal. Estos tumores pueden localizarse a lo largo de todo el tubo digestivo, aunque son más frecuentes en estómago e intestino delgado. Clínicamente se manifiestan como una anemia secundaria a un sangrado intestinal. Son raros los cuadros abdominales agudos por perforación o necrosis. Presentamos el caso de un tumor estromal yeyunal con necrosis masiva liquefactiva, lo cual le confiere unas características radiológicas peculiares (AU)
