Philipp TM, Gong W, Köhnlein K, Ohse VA, Müller FI, Priebs J, Steinbrenner H, Klotz LO. SEMO-1, a novel methanethiol oxidase in Caenorhabditis elegans, is a pro-aging factor conferring selective stress resistance.
Biofactors 2022;
48:699-706. [PMID:
35316559 DOI:
10.1002/biof.1836]
[Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 03/04/2022] [Indexed: 01/21/2023]
Abstract
Methanethiol is a toxic gas produced through bacterial degradation of sulfur-containing amino acids. Applying a novel enzymatic assay, we here identified a methanethiol oxidase (MTO) that catalyzes the degradation of methanethiol in the nematode Caenorhabditis elegans (C. elegans). The corresponding protein, Y37A1B.5, previously characterized as a C. elegans ortholog of human selenium-binding protein 1 (SELENBP1), was renamed SEMO-1 (SELENBP1 ortholog with methanethiol oxidase activity). Worms rendered deficient in SEMO-1 not only showed decreased hydrogen sulfide production from methanethiol catabolism but they were also more resistant to oxidative stress and had an elevated life span. In contrast, resistance to selenite was significantly lowered in SEMO-1-deficient worms. Naturally occurring mutations of human SELENBP1 were introduced to recombinant SEMO-1 through site-directed mutagenesis and resulted in loss of its MTO activity, indicating a similar enzymatic mechanism for SELENBP1 and SEMO-1. In summary, SEMO-1 confers resistance to toxic selenite and the ability to metabolize toxic methanethiol. These beneficial effects might be a trade-off for its negative impact on C. elegans life span.
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