Clonostachys rosea demethiolase STR3 controls the conversion of methionine into methanethiol

Eukaryote-derived methioninase, catalyzing the one-step degradation of methionine (Met) to methanethiol (MTL), has received much attention for its low immunogenic potential and use as a therapeutic agent against Met-dependent tumors. Although biological and chemical degradation pathways for Met-MTL conversion are proposed, the concrete molecular mechanism for Met-MTL conversion in eukaryotes is still unclear. Previous studies demonstrated that α-keto-methylthiobutyric acid (KMBA), the intermediate for Met-MTL conversion, was located extracellularly and the demethiolase STR3 possessed no activities towards Met, which rule out the possibility of intracellular Met-MTL conversion pathway inside eukaryotes. We report here that degradation of Met resulted in intracellular accumulation of KMBA in Clonostachys rosea. Addition of Met to culture media led to the production of MTL and downregulation of STR3, while incubation of Met with surrogate substrate α-ketoglutaric acid enhanced the synthesis of MTL and triggered the upregulation of STR3. Subsequent biochemical analysis with recombinant STR3 showed that STR3 directly converted both Met and its transamination product KMBA to MTL. These results indicated that STR3 as rate-limiting enzyme degrades Met and KMBA into MTL. Our findings suggest STR3 is a potential target for therapeutic agents against Met-dependent tumors and aging.

Medienart:

E-Artikel

Erscheinungsjahr:

2016

Erschienen:

2016

Enthalten in:

Zur Gesamtaufnahme - volume:6

Enthalten in:

Scientific reports - 6(2016) vom: 23. Feb., Seite 21920

Sprache:

Englisch

Beteiligte Personen:

Jia, Kai-Zhi [VerfasserIn]
Zhang, Quan [VerfasserIn]
Sun, Lin-Yang [VerfasserIn]
Xu, Yang-Hua [VerfasserIn]
Li, Hong-Mei [VerfasserIn]
Tang, Ya-Jie [VerfasserIn]

Links:

Volltext

Themen:

2-keto-4-methylthiobutyric acid
2X8406WW9I
583-92-6
AE28F7PNPL
Carbon-Sulfur Lyases
Culture Media
EC 4.4.-
EC 4.4.1.11
Fungal Proteins
Journal Article
Ketoglutaric Acids
L-methionine gamma-lyase
Methionine
Methylmercaptan
Recombinant Proteins
Research Support, Non-U.S. Gov't
Sulfhydryl Compounds

Anmerkungen:

Date Completed 21.12.2016

Date Revised 05.06.2019

published: Electronic

Citation Status MEDLINE

doi:

10.1038/srep21920

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM257726519