PMID- 26237084
OWN - NLM
STAT- MEDLINE
DCOM- 20161213
LR  - 20210617
IS  - 1554-8635 (Electronic)
IS  - 1554-8627 (Print)
IS  - 1554-8627 (Linking)
VI  - 12
IP  - 2
DP  - 2016
TI  - Autophagy of cytoplasmic bulk cargo does not require LC3.
PG  - 439-41
LID - 10.1080/15548627.2015.1076606 [doi]
AB  - To investigate the role of LC3 in bulk autophagy we compared its 
      autophagic-lysosomal processing (using an improved quantitative immunoblotting 
      method) with autophagic-lysosomal bulk cargo flux (measured by our established 
      LDH [lactate dehydrogenase] sequestration assay) in amino acid-starved rat 
      hepatocytes treated with cycloheximide to prevent new LC3 influx. Block-release 
      experiments with the reversible autophagy inhibitors 3-methyladenine (3MA) and 
      thapsigargin (TG) showed that while only 3MA suppressed phagophoric LC3 
      attachment (lipidation), both inhibitors prevented phagophore closure (cargo 
      sequestration). Upon release from closure blockade, some autophagic-lysosomal LC3 
      flux was resumed even in the presence of 3MA, i.e., without an accompanying bulk 
      cargo flux. Conversely, whereas the autophagic-lysosomal flux of LC3 halted 
      within  approximately 100 min of cycloheximide treatment, the bulk cargo flux continued at a 
      high rate. siRNA-mediated knockdown of LC3 family proteins in LNCaP prostate 
      carcinoma cells confirmed that autophagy of cytoplasmic bulk cargo was completely 
      LC3 independent also in these cells, and in the absence of cycloheximide. 
      However, a strong requirement for GABARAP family proteins was evident. Since bulk 
      autophagy of cytoplasm (macroautophagy) and autophagic-lysosomal LC3 processing 
      may apparently be mutually independent, LC3 would seem to be unsuitable as a 
      general indicator of autophagy.
FAU - Engedal, Nikolai
AU  - Engedal N
AD  - a Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of 
      Oslo , Oslo , Norway.
FAU - Seglen, Per O
AU  - Seglen PO
AD  - a Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of 
      Oslo , Oslo , Norway.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20150803
PL  - United States
TA  - Autophagy
JT  - Autophagy
JID - 101265188
RN  - 0 (LC3 protein, rat)
RN  - 0 (MAP1LC3A protein, human)
RN  - 0 (Microtubule-Associated Proteins)
RN  - 5142-23-4 (3-methyladenine)
RN  - 67526-95-8 (Thapsigargin)
RN  - 98600C0908 (Cycloheximide)
RN  - JAC85A2161 (Adenine)
SB  - IM
MH  - Adenine/analogs & derivatives/pharmacology
MH  - Animals
MH  - *Autophagy
MH  - Cell Line, Tumor
MH  - Cycloheximide/pharmacology
MH  - Cytoplasm/drug effects/*metabolism
MH  - Hepatocytes/cytology/metabolism
MH  - Humans
MH  - Microtubule-Associated Proteins/*metabolism
MH  - Rats
MH  - Thapsigargin/pharmacology
PMC - PMC4836025
OTO - NOTNLM
OT  - 3-methyladenine
OT  - GABARAP
OT  - LC3
OT  - autophagy
OT  - density gradient
OT  - hepatocyte
OT  - liver
OT  - lysosome
OT  - thapsigargin
EDAT- 2015/08/04 06:00
MHDA- 2016/12/15 06:00
PMCR- 2016/08/03
CRDT- 2015/08/04 06:00
PHST- 2015/08/04 06:00 [entrez]
PHST- 2015/08/04 06:00 [pubmed]
PHST- 2016/12/15 06:00 [medline]
PHST- 2016/08/03 00:00 [pmc-release]
AID - 1076606 [pii]
AID - 10.1080/15548627.2015.1076606 [doi]
PST - ppublish
SO  - Autophagy. 2016;12(2):439-41. doi: 10.1080/15548627.2015.1076606. Epub 2015 Aug 
      3.