The GST-BHMT assay reveals a distinct mechanism underlying proteasome inhibition-induced macroautophagy in mammalian cells.

ACACA/B acetyl-CoA carboxylase α/β ACTB actin β ATF4 activating transcription factor 4 ATF6 activating transcription factor 6 ATG7 autophagy-related 7 BCL2 B-cell CLL/lymphoma 2 BECN1 Beclin 1 autophagy-related BHMT BHMT betaine-homocysteine S-methyltransferase Baf A1 bafilomycin A1 CTNNB1 catenin (cadherin-associated protein) β 1 88kDa Cvt cytoplasm-to-vacuole-targeting DDIT3 DNA-damage-inducible transcript 3 EBSS Earle's Balanced Salt Solution EIF2AK3 eukaryotic translation initiation factor 2-α kinase 3 EIF4EBP1 eukaryotic translation initiation factor 4E binding protein 1 ER endoplasmic reticulum ERN1 endoplasmic reticulum to nucleus signaling 1 GST glutathionine S-transferase GST-BHMT(FRAG) an autophagy-mediated cleavage product of the GST-BHMT reporter GST-BHMT a fusion protein of glutathionine S-transferase N-terminal to betaine-homocysteine S-methyltransferase HA hemagglutinin HSPA5 heat shock 70kDa protein 5 (glucose-regulated protein 78kDa) LSCS linker-specific cleavage site MAP1LC3 microtubule-associated protein 1 light chain 3 MAP2K7 mitogen-activated protein kinase kinase 7 MAPK8 mitogen-activated protein kinase 8 MTOR MTOR mechanistic target of rapamycin (serine/threonine kinase) MTORC1 MTOR complex 1 NBR1 neighbor of BRCA1 gene 1 P4HB prolyl 4-hydroxylase β polypeptide PRKAA protein kinase AMP-activated α catalytic subunit PRKAA/AMPK RHEB Ras homolog enriched in brain RM rich medium RPS6KB1 ribosomal protein S6 kinase 70kDa polypeptide 1 SQSTM1 sequestosome 1 TSC1/2 tuberous sclerosis 1/2 ULK1 unc-51 like autophagy activating kinase 1 UPR unfolded protein response UPS ubiquitin proteasome system XBP1 X-box binding protein 1 cargo receptors SQSTM1/p62 and NBR1 proteasome inhibition selective macroautophagy