Dron Michel, Bailly Yannick, Beringue Vincent, Haeberlé Anne-Marie, Griffond Bernadette, Risold Pierre-Yves, Tovey Michael G, Laude Hubert, Dandoy-Dron Françoise
CNRS UPR-9045, Laboratoire d'Oncologie Virale, Villejuif, France.
Autophagy. 2006 Jan-Mar;2(1):58-60. doi: 10.4161/auto.2228. Epub 2006 Jan 10.
The Scrg1 gene was initially discovered as one of the genes upregulated in transmissible spongiform encephalopathies (TSE). Scrg1 encodes a highly conserved, cysteine-rich protein expressed principally in the central nervous system. The protein is targeted to the Golgi apparatus and large dense-core vesicles/secretory granules in neurons. We have recently shown that the Scrg1 protein is widely induced in neurons of scrapie-infected mice, suggesting that Scrg1 is involved in the host response to stress and/or the death of neurons. At the ultrastructural level, Scrg1 is associated with dictyosomes of the Golgi apparatus and autophagic vacuoles of degenerative neurons. It is well known that apoptosis plays a major role in the events leading to neuronal cell death in TSE. However, autophagy was identified in experimentally induced scrapie a long time ago and was recently reevaluated as a possible cell death program in prion diseases. The consistent association of Scrg1 with autophagic structures typical of scrapie is in agreement with the recruitment of Golgi-specific proteins in this degradation process and we suggest that Scrg1 might be used as a specific probe to identify neuronal autophagy in TSE.
