Fig. 7: The proposed mechanism for the role of BCAT1 in PASMC autophagy.

a Hypoxia causes ZNF423 to shuttle from the nucleus to the cytoplasm, where it binds the AREs of the 3′-UTR of BCAT1 mRNA, promoting BCAT1 translation and increasing BCAT1 expression. Then, BCAT1 binds IRE1 on the endoplasmic reticulum to activate RE stress pathway proteins and the XBP1 and RIDD pathways downstream of IRE1, constituting an IRE1-XBP1-RIDD cell axis, ultimately inducing autophagy activation in PASMCs.