Mtg2, also known as GTPBP5, is a mitochondrial protein belonging to the Obg family. It plays a crucial role in the biogenesis of mammalian mitochondrial ribosomes (mitoribosomes), specifically facilitating the maturation of the large mitoribosome subunit (mtLSU) by ensuring efficient methylation of two 16S rRNA residues [2]. This ultimately coordinates subunit joining, serving as a quality control checkpoint during mtLSU assembly to ensure the formation of the mature 55S monosome.

In a study on Asian neovascular age-related macular degeneration (nAMD) subtypes, at the GATA binding protein 5 (GATA5) locus, the expressions of genes including Mtg2 were significantly induced during retinal angiogenesis and subretinal fibrosis in murine models [1]. Also, in the filamentous fungus Botrytis cinerea, the ortholog BcMtg2 is required for asexual development, environmental stress response, and pathogenicity as its deletion mutant showed defects in spore production, conidial germination, sclerotial formation, and increased sensitivity to various environmental stresses [3].

In conclusion, Mtg2 is essential for mitoribosome maturation, which has implications for normal cellular function. Its altered expression in models related to nAMD and its role in the development and stress response of Botrytis cinerea suggest its importance in both mammalian disease-related processes and fungal biology. The study of Mtg2 using gene knockout models in these contexts provides insights into disease mechanisms and fungal pathogenicity.

References:

1. Fan, Qiao, Li, Hengtong, Wang, Xiaomeng, Cheung, Chui Ming Gemmy, Cheng, Ching-Yu. 2023. Contribution of common and rare variants to Asian neovascular age-related macular degeneration subtypes. In Nature communications, 14, 5574. doi:10.1038/s41467-023-41256-z. https://pubmed.ncbi.nlm.nih.gov/37696869/

2. Maiti, Priyanka, Antonicka, Hana, Gingras, Anne-Claude, Shoubridge, Eric A, Barrientos, Antoni. . Human GTPBP5 (MTG2) fuels mitoribosome large subunit maturation by facilitating 16S rRNA methylation. In Nucleic acids research, 48, 7924-7943. doi:10.1093/nar/gkaa592. https://pubmed.ncbi.nlm.nih.gov/32652011/

3. Shao, Wenyong, Zhang, Yu, Wang, Jin, Lv, Chiyuan, Chen, Changjun. 2016. BcMtg2 is required for multiple stress tolerance, vegetative development and virulence in Botrytis cinerea. In Scientific reports, 6, 28673. doi:10.1038/srep28673. https://pubmed.ncbi.nlm.nih.gov/27346661/