SCRG1, a potential marker of autophagy in transmissible spongiform encephalopathies.
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.
Dron
Michel
M
CNRS UPR-9045, Laboratoire d'Oncologie Virale, Villejuif, France.
Bailly
Yannick
Y
Beringue
Vincent
V
Haeberlé
Anne-Marie
AM
Griffond
Bernadette
B
Risold
Pierre-Yves
PY
Tovey
Michael G
MG
Laude
Hubert
H
Dandoy-Dron
Françoise
F
D000818:Animals; D001343:Autophagy; D015415:Biomarkers / Q000032:analysis; D051379:Mice; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009474:Neurons / Q000737:chemistry / Q000648:ultrastructure; D017096:Prion Diseases / Q000378:metabolism / Q000473:pathology*
D015415:Biomarkers; D009419:Nerve Tissue Proteins; C111496:Scrg1 protein, mouse