What are the three arms of the unfolded protein response?
The three UPR arms are IRE1, ATF6, and PERK
The lecture connects IRE1 with XBP1/bZIP60/HAC1, ATF6 with ATF6/bZIP28, and PERK with eIF2α phosphorylation
What is the role/mode of action of IRE1?
IRE1 is an ER stress sensor with endoribonuclease activity that becomes activated and performs mRNA splicing of downstream UPR regulators
What is the role of XBP1, bZIP60 or HAC1?
XBP1, bZIP60, and HAC1 are transcription factors activated by IRE1-mediated splicing that induce expression of UPR target genes
What is the mode of action of ATF6/bZIP28?
ATF6/bZIP28 relocates from the ER to the Golgi, where it is proteolytically cleaved; the released fragment enters the nucleus and activates UPR genes
What is the mode of action of PERK?
PERK is an ER stress sensor kinase that phosphorylates eIF2α, thereby attenuating general translation during ER stress.
What are the domains of PERK?
PERK has an ER-luminal stress-sensing domain, a transmembrane domain, and a cytosolic kinase domain.
How does PERK regulate translation?
PERK regulates translation by phosphorylating eIF2α, which inhibits translation initiation and lowers the folding load on the ER.
Which UPR arms exist in plants, mammals and yeast?
In mammals, all three arms exist: IRE1, ATF6, PERK; in yeast, the lecture supports the IRE1–HAC1 branch; in plants, the lecture supports IRE1–bZIP60 and ATF6-like bZIP28, with ER stress also linked to eIF2α-related translational control
Zuletzt geändertvor 2 Tagen