[HTML][HTML] A conserved CCM complex promotes apoptosis non-autonomously by regulating zinc homeostasis

EM Chapman, B Lant, Y Ohashi, B Yu… - Nature …, 2019 - nature.com
EM Chapman, B Lant, Y Ohashi, B Yu, M Schertzberg, C Go, D Dogra, J Koskimäki, R Girard
Nature communications, 2019nature.com
Apoptotic death of cells damaged by genotoxic stress requires regulatory input from
surrounding tissues. The C. elegans scaffold protein KRI-1, ortholog of mammalian
KRIT1/CCM1, permits DNA damage-induced apoptosis of cells in the germline by an
unknown cell non-autonomous mechanism. We reveal that KRI-1 exists in a complex with
CCM-2 in the intestine to negatively regulate the ERK-5/MAPK pathway. This allows the KLF-
3 transcription factor to facilitate expression of the SLC39 zinc transporter gene zipt-2. 3 …
Abstract
Apoptotic death of cells damaged by genotoxic stress requires regulatory input from surrounding tissues. The C. elegans scaffold protein KRI-1, ortholog of mammalian KRIT1/CCM1, permits DNA damage-induced apoptosis of cells in the germline by an unknown cell non-autonomous mechanism. We reveal that KRI-1 exists in a complex with CCM-2 in the intestine to negatively regulate the ERK-5/MAPK pathway. This allows the KLF-3 transcription factor to facilitate expression of the SLC39 zinc transporter gene zipt-2.3, which functions to sequester zinc in the intestine. Ablation of KRI-1 results in reduced zinc sequestration in the intestine, inhibition of IR-induced MPK-1/ERK1 activation, and apoptosis in the germline. Zinc localization is also perturbed in the vasculature of krit1−/− zebrafish, and SLC39 zinc transporters are mis-expressed in Cerebral Cavernous Malformations (CCM) patient tissues. This study provides new insights into the regulation of apoptosis by cross-tissue communication, and suggests a link between zinc localization and CCM disease.
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