RRC ID 48824
Author Sato M, Seki T, Konno A, Hirai H, Kurauchi Y, Hisatsune A, Katsuki H.
Title Fluorescent-based evaluation of chaperone-mediated autophagy and microautophagy activities in cultured cells.
Journal Genes Cells
Abstract The autophagy-lysosome protein degradation is further classified into macroautophagy (MA), microautophagy (mA), and chaperone-mediated autophagy (CMA). While MA is involved in various functions and disease pathogenesis, little is known about CMA and mA because of the absence of easy methods to assess their activities. We have recently established a method to assess CMA activity using glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a CMA substrate, and HaloTag (HT) system. Another group has recently identified a mammalian mA pathway, in which substrates are delivered to late endosomes in an heat shock cognate protein (Hsc)70-dependent manner. Because Hsc70 is also involved in CMA, our method would detect both CMA and mA activities. In this study, we attempted to assess CMA and mA activities separately through the siRNA-mediated knockdown of CMA- and mA-related proteins. Knockdown of LAMP2A, a CMA-related protein, and TSG101, an mA-related protein, significantly but only partially decreased the punctate accumulation of GAPDH-HT in AD293 cells and primary cultured rat cortical neurons. Compounds that activate CMA significantly increased GAPDH-HT puncta in TSG101-knockdown cells, but not in LAMP2A-knockdown cells, suggesting that punctate accumulation of GAPDH-HT under LAMP2A- and TSG101-knockdown represents mA and CMA activities, respectively. We succeeded in establishing the method to separately evaluate CMA and mA activities by fluorescence observation.
Volume 21(8)
Pages 861-73
Published 2016-8-1
DOI 10.1111/gtc.12390
PMID 27377049
MeSH Animals Autophagy / genetics* DNA-Binding Proteins / genetics* Endosomal Sorting Complexes Required for Transport / genetics* Endosomes / metabolism Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+) / biosynthesis* Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+) / genetics HEK293 Cells Humans Lysosome-Associated Membrane Glycoproteins / genetics* Lysosomes / genetics Lysosomes / metabolism Molecular Chaperones / genetics Molecular Chaperones / isolation & purification Neoplasm Proteins / genetics* Neurons / metabolism Proteolysis Rats Transcription Factors / genetics*
IF 1.655
Times Cited 14
DNA material pcDNA5-GAPDH-HaloTag (RDB15088)