Xie, W.-J. | bioRxiv Science

bioRxiv2024

Calcium Homeostasis Modulator 2 Constitutes an ATP-regulation Pore in Mitochondria

Recent structural analyses showed that the calcium homeostasis modulator-2 (CALHM2) forms a mega channel, but its cellular location and endogenous function are yet unknown. We found that native CALHM2 resides on the mitochondrial inner membrane and constitutes an ATP-regulated ATP release channel. CALHM2 knockdown/knockout decreases cytosolic ATP concentration, and thereby compromises energy-sensitive processes, such as intracellular Ca2+ handling. However, CALHM2 loss-of-function elevates ATP concentration in the mitochondrial matrix, dephosphorylates key enzymes in the mammalian target of rapamycin (mTOR) pathway, and promotes longevity in CALHM2 knockout mice. These findings reveal that CALHM2 constitutes a novel regulator of mitochondrial metabolism, which may have important implications in aging and diseases.

cell biology↗

bioRxiv2020

Isolation and Characterization of 2019-nCoV-like Coronavirus from Malayan Pangolins

The outbreak of 2019-nCoV in the central Chinese city of Wuhan at the end of 2019 poses unprecedent public health challenges to both China and the rest world1. The new coronavirus shares high sequence identity to SARS-CoV and a newly identified bat coronavirus2. While bats may be the reservoir host for various coronaviruses, whether 2019-nCoV has other hosts is still ambiguous. In this study, one coronavirus isolated from Malayan pangolins showed 100%, 98.2%, 96.7% and 90.4% amino acid identity with 2019-nCoV in the E, M, N and S genes, respectively. In particular, the receptor-binding domain of the S protein of the Pangolin-CoV is virtually identical to that of 2019-nCoV, with one amino acid difference. Comparison of available genomes suggests 2019-nCoV might have originated from the recombination of a Pangolin-CoV-like virus with a Bat-CoV-RaTG13-like virus. Infected pangolins showed clinical signs and histopathological changes, and the circulating antibodies reacted with the S protein of 2019-nCoV. The isolation of a coronavirus that is highly related to 2019-nCoV in the pangolins suggests that these animals have the potential to act as the intermediate host of 2019-nCoV. The newly identified coronavirus in the most-trafficked mammal could represent a continuous threat to public health if wildlife trade is not effectively controlled.

microbiology↗