Silva A, Almeida B, Sampaio-Marques B, Reis M I R, Ohlmeier S, Rodrigues F, Vale A do, Ludovico P
Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.
Biochim Biophys Acta. 2011 Dec;1813(12):2044-9. doi: 10.1016/j.bbamcr.2011.09.010. Epub 2011 Oct 1.
Yeast metacaspase (Yca1p) is required for the execution of apoptosis upon a wide range of stimuli. However, the specific degradome of this yeast protease has not been unraveled so far. By combining different methodologies described as requisites for a protein to be considered a protease substrate, such as digestome analysis, cleavage of recombinant GAPDH by metacaspase and evaluation of protein levels in vivo, we show that upon H(2)O(2)-induced apoptosis, the metabolic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a specific target of metacaspase. Nitric oxide (NO) signaling, which mediates H(2)O(2)-induced apoptosis, is required for metacaspase specific GAPDH cleavage. In conclusion, in this work we identified GAPDH as the first direct yeast metacaspase substrate described so far. Although mammalian caspases and yeast metacaspase apparently have distinct target cleavage sites, GAPDH arises as a common substrate for these proteases.
酵母metacaspase（Yca1p）在多种刺激诱导的细胞凋亡执行过程中是必需的。然而，到目前为止，这种酵母蛋白酶的具体降解组尚未被阐明。通过结合被描述为蛋白质被视为蛋白酶底物所需的不同方法，如消化组分析、metacaspase对重组甘油醛-3-磷酸脱氢酶（GAPDH）的切割以及体内蛋白质水平的评估，我们发现，在过氧化氢（H₂O₂）诱导的细胞凋亡过程中，代谢酶甘油醛-3-磷酸脱氢酶（GAPDH）是metacaspase的特异性靶点。介导H₂O₂诱导细胞凋亡的一氧化氮（NO）信号传导是metacaspase特异性切割GAPDH所必需的。总之，在这项研究中，我们将GAPDH鉴定为迄今为止描述的首个直接的酵母metacaspase底物。尽管哺乳动物半胱天冬酶和酵母metacaspase显然具有不同的靶切割位点，但GAPDH却是这些蛋白酶的共同底物。
