Proper protein folding in the ER is vital to maintain cellular homeostasis. In this sense, there is a growing interest in the identification, as in the case of AtHOP3, of new regulators in this process.
The endoplasmic reticulum (ER) is the organelle where the proteins that are transported to the membrane or secreted are folded. Under different abiotic and biotic stresses, as well as during specific plant developmental processes, the demand for protein folding in the ER is exceeded, leading to a high accumulation of misfolded proteins known as "ER stress”. This ER stress is toxic for the cell and should be alleviated in order to maintain protein homeostasis.
In this paper, we have described that Arabidopsis HOP3, which belong to the HSP70-HSP90 organizing protein family (HOP), interacts with an essential protein involved in protein folding in the ER, the chaperone BiP. In addition, we have demonstrated that