2010年6月1日 · The first chaperone that contacts post-translationally imported proteins like CPY* in yeast is the Hsp70 Kar2, the orthologue of mammalian BiP. Kar2 binds short hydrophobic patches of incoming proteins and is tethered to the ER membrane by virtue of Sec63, an integral membrane partner of Sec61.

ERAD：内质网相关蛋白降解(ER-associated degradation)； ERQC： 内质网质控 (ER quality control)。 UPR的机理在细胞生物学的课程中就说过，没有学过的读者也不用担心，请读文。正常生理条件下，几种感应蛋白 IRE1 、 PERK 、 ATF6 等，与分子伴侣BiP/ GRP78 / Kar2 形成稳定 …

2011年12月21日 · Its application to KAR2 revealed a specific role of elevated chaperone levels to mitigate stress by ridding misfolded proteins through the ERAD and ER-to-vacuole pathways. Because the UPR regulates genes with functions as diverse as glycosylation and proteasome biogenesis, it is a major homeostatic pathway of the cell ( Travers et al. , 2000 ...

2021年3月1日 · Kar2 can maintain the solubility of ERAD substrates as a chaperone. Taken together, gpERAD substrates appear to have two routes to reach the retrotranslocon. The first is that gpERAD substrate bound to Kar2 binds to Yos9 after mannose trimming to M7A, and the three-protein complex binds to Hrd3 for subsequent degradation via Hrd1.

2006年2月1日 · In the lumen of the endoplasmic reticulum (ER), Kar2p binds to secretory and transmembrane precursor proteins to prevent their misfolding (1, 7). Kar2p also facilitates protein translocation into the ER (10), membrane fusion during karyogamy (7), and ER-associated degradation (13).

Unfolded/misfolded proteins that cannot be repaired are degraded via the ER-associated degradation (ERAD) pathway, which decreases productivity. Co-expression of selected UPR genes, along with the recombinant gene of interest, is a common approach to enhance the production of properly folded, secreted proteins.

1999年2月5日 · Polypeptide import into the yeast endoplasmic reticulum (ER) requires two hsp70s, Ssa1p in the cytosol and BiP (Kar2p) in the ER lumen. After import, aberrant polypeptides may be exported to the cytoplasm for degradation by the proteasome, and defects in the ER chaperone calnexin (Cne1p) compromise their degradation.

2003年4月17日 · ER-associated degradation (ERAD) removes defective and mis-folded proteins from the eukaryotic secretory pathway, but mutations in the ER lumenal Hsp70, BiP/Kar2p, compromise ERAD efficiency in yeast.

ER-associated degradation (ERAD) removes defective and mis-folded proteins from the eukaryotic secretory pathway, but mutations in the ER lumenal Hsp70, BiP/Kar2p, compromise ERAD efficiency in yeast. Because attenuation of ERAD activates the UPR, we screened for kar2 mutants in which the unfolded p …

2013年3月6日 · Constitutive expression of KAR2 by the strong histone H3 promoter partially restores resistance to ER stress, cell wall stress, thermotolerance, and genotoxic stress in ire1Δ and hxl1Δ mutants, suggesting that Kar2 mainly functions downstream of the UPR pathway.