| First Author | Son J | Year | 2022 |
| Journal | J Invest Dermatol | Volume | 142 |
| Issue | 6 | Pages | 1682-1691.e7 |
| PubMed ID | 34808241 | Mgi Jnum | J:324913 |
| Mgi Id | MGI:7281289 | Doi | 10.1016/j.jid.2021.11.010 |
| Citation | Son J, et al. (2022) The Endoplasmic Reticulum Stress Sensor IRE1alpha Regulates the UV DNA Repair Response through the Control of Intracellular Calcium Homeostasis. J Invest Dermatol 142(6):1682-1691.e7 |
| abstractText | The unfolded protein response is activated by UVB irradiation, but the role of a key mediator, IRE1alpha, is not clear. In this study, we show that mice with an epidermal IRE1alpha deletion are sensitized to UV with increased apoptosis, rapid loss of UV-induced cyclopyrimidine dimerpositive keratinocytes, and sloughing of the epidermis. In vitro, Ire1alpha-deficient keratinocytes have increased UVB sensitivity, reduced cyclopyrimidine dimer repair, and reduced accumulation of gammaH2AX and phosphorylated ATR, suggesting defective activation of nucleotide excision repair. Knockdown of XBP1 or pharmacologic inhibition of the IRE1alpha ribonuclease did not phenocopy Ire1alpha deficiency. The altered UV response was linked to elevated intracellular calcium levels and ROS, and this was due to dysregulation of the endoplasmic reticulum calcium channel InsP3R. Pharmacologic, genetic, and biochemical studies linked the regulation of the Ins3PR, intracellular calcium, and normal UV DNA damage response to CIB1 and the IRE1alphaTRAF2ASK1 complex. These results suggest a model where IRE1alpha activation state drives CIB1 binding either to the InsP3R or ASK1 to regulate endoplasmic reticulum calcium efflux, ROS, and DNA repair responses after UV irradiation. |
