MTALTND4, a second protein coded by <i>nd4</i> impacts mitochondrial bioenergetics

Kienzle, Laura; Bettinazzi, Stefano; Brunet, Marie-Christine; Choquette, Thierry; Khorami, Hajar Hosseini; Roucou, Xavier; Landry, Christian R.; Angers, Annie; Breton, Sophie

doi:10.1101/2022.04.28.489924

Cited by 1 publication

(1 citation statement)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In cnidarians, sponges and placozoans, protein-coding genes with non-OXPHOS functions (e.g., dnaB , tatC ) have been also reported [ 25 , 26 ]. Surprisingly, nine additional mtDNA-encoded protein genes have been described in humans [ 27 – 30 ], one of which is a 75 bp ORF in the mitochondrial 16S rRNA that acts as a neuroprotector, an antiapoptotic agent, and a cytoprotector [ 31 , 32 ]. These discoveries indicate that there are additional functional sequences in mitochondria, maybe related to its diverse functions.…”

Section: Introductionmentioning

confidence: 99%

A comparative analysis of mitochondrial ORFs provides new insights on expansion of mitochondrial genome size in Arcidae

Zhang

Halanych

et al. 2022

BMC Genomics

View full text Add to dashboard Cite

Background Arcidae, comprising about 260 species of ark shells, is an ecologically and economically important lineage of bivalve mollusks. Interestingly, mitochondrial genomes of several Arcidae species are 2–3 times larger than those of most bilaterians, and are among the largest bilaterian mitochondrial genomes reported to date. The large mitochondrial genome size is mainly due to expansion of unassigned regions (regions that are functionally unassigned). Previous work on unassigned regions of Arcidae mtDNA genomes has focused on nucleotide-level analyses to observe sequence characteristics, however the origin of expansion remains unclear. Results We assembled six new mitogenomes and sequenced six transcriptomes of Scapharca broughtonii to identify conserved functional ORFs that are transcribed in unassigned regions. Sixteen lineage-specific ORFs with different copy numbers were identified from seven Arcidae species, and 11 of 16 ORFs were expressed and likely biologically active. Unassigned regions of 32 Arcidae mitogenomes were compared to verify the presence of these novel mitochondrial ORFs and their distribution. Strikingly, multiple structural analyses and functional prediction suggested that these additional mtDNA-encoded proteins have potential functional significance. In addition, our results also revealed that the ORFs have a strong connection to the expansion of Arcidae mitochondrial genomes and their large-scale duplication play an important role in multiple expansion events. We discussed the possible origin of ORFs and hypothesized that these ORFs may originate from duplication of mitochondrial genes. Conclusions The presence of lineage-specific mitochondrial ORFs with transcriptional activity and potential functional significance supports novel features for Arcidae mitochondrial genomes. Given our observation and analyses, these ORFs may be products of mitochondrial gene duplication. These findings shed light on the origin and function of novel mitochondrial genes in bivalves and provide new insights into evolution of mitochondrial genome size in metazoans.

show abstract