Biology subjects

Battersby, B.

Publications and source records attributed to Battersby, B..

5 recordsLinked to original sources

bioRxiv2026

Rapid plastid isolation reveals the chloroplast proteome and structures of the chlororibosome large subunit and RuBisCO in Marchantia polymorpha

Plastids house the biology of eukaryotic photosynthesis. While 1000s of plastid genomes have been sequenced, the availability of less than ten proteomes and only two species with full 70S plastid ribosomal structures limit our understanding of plant evolution. We optimized a protocol for the rapid isolation of Marchantia polymorpha plastids that provides a highly enriched and intact organelle fraction from gradient volumes as little as 2 mL. The approach was successfully applied to six other species. Focusing on M. polymorpha, we determined the proteome of the plastid fraction, identifying 1337 nuclear-encoded proteins with a high confidence, where 83% belong to orthologs shared with angiosperms. We further isolated protein complexes by RNA affinity purification using poly-lysine and provide the high-resolution structures of the 50S subunit of the chloroplast ribosome and RuBisCO using cryogenic EM and image reconstruction to 2.23 and 2.12 [A] resolution, respectively. For plastids, our data show that the genome reduction event experienced by the bryophyte common ancestor has had little impact on the organelles complexity and they underscore a high level of structural conservation of key components. Our data provide novel resources to explore the functional evolution of plastid proteomes and major macromolecular complexes of cyanobacterial origin.

plant biology↗

bioRxiv2026

Structure determination and dual targeting of a plant TACO1 identifies its ancient role as an organelle translation regulator

Ribosome stalling caused by polyproline (PPs) motifs is common. Their translation is enhanced by accessory proteins such as YebC in bacteria, whose homolog, TRANSLATIONAL ACTIVATOR OF CYTOCHROME C OXIDASE 1 (TACO1), aids the translation of mitochondria-encoded proteins. The prevalence of PP motifs across plastid-encoded genes and their impact on the translation of photosynthesis-relevant proteins remains unexplored. Equally, a translation-enhancer of PP motifs equivalent to TACO1 for plastid ribosomes has not been reported. Here, we show that plastid genomes encode 24 proteins with a minimum of one PP motif on average, half of which are conserved in their cyanobacterial homologs, and that the vast majority of eukaryotes, including plants, encode a single TACO1 that we demonstrate to be dually targeted to mitochondria and plastids of Marchantia polymorpha. We resolved the MpTACO1 structure at 2.34 [A] by X-ray crystallography and the flexibility by small-angle X-ray scattering. Through modelling, we demonstrate that MpTACO1 can fit into the peptidyl transfer centre of plant chlororibosomes in a similar manner as human TACO1 in the mitoribosome. The identification and structure determination of the first plastid-targeted YebC/TACO1 allows us to sketch a unified model for the function and evolution of this ancient family of ribosomal accessory proteins, underscoring their indispensable role in the translation of bioenergetic membrane proteins reaching back almost 4 billion years. HighlightsO_LIDozens of GC-rich polyproline (PP) encoding regions are retained by AT-rich genomes C_LIO_LIPP motif conservation hints at regulatory mechanisms and required translation pauses C_LIO_LIChloroplast targeting of a (mitochondrial) translation enhancer of PP motifs C_LIO_LIMpTACO1 structure at 2.34 [A] resolution demonstrates its high level of conservation C_LI

plant biology↗

bioRxiv2021

Convergent evolution of mevalonate pathway in Inonotus obliquus and Betula pendula.

Inonotus obliquus, Chaga mushroom, is a fungal species from Hymenochaetaceae family (Basidiomycota) which has been widely used for traditional medicine in Europe and Asia. Here, chaga genome was sequenced using Pacbio sequencing into a 50.7Mbp assembly consisting of 301 primary contigs with an N50 value of 375 kbp. Genome evolution analyses revealed a lineage-specific whole genome duplication event and an expansion of Cytochrome P450 superfamily. Fungal biosynthetic clusters were enriched for tandemly duplicated genes, suggesting that biosynthetic pathway evolution has proceeded through small-scale duplications. Metabolomic fingerprinting confirmed a highly complex terpene biosynthesis chemistry when compared against related fungal species lacking the genome duplication event.

evolutionary biology↗

bioRxiv2021

RNA nucleotide repeats induce mitochondrial dysfunction and the ribosome associated quality control

Nucleotide repeat sequences are prevalent in the genome and expansion of these sequences is associated with more than 40 neuromuscular disorders. To understand the pathogenic mechanisms underlying RNA-repeat toxicity, we performed a genetic screen in a Caenorhabditis elegans model expressing an expanded CUG repeat specifically in the muscle. Here, we show that expression of this RNA repeat impairs motility by mitochondrial dysfunction, disrupting mitochondrial morphology and respiration. The phenotype is dependent on the RNA-binding factor MBL-1 and requires factors from the ribosome-associated protein quality control complex. Furthermore, Coenzyme Q supplementation rescued the motility impairment and all of the mitochondrial phenotypes. Together, our data reveal the importance of mitochondrial dysfunction in the molecular pathogenesis of RNA repeat expansion disorders.

genetics↗

bioRxiv2021

Translation of MT-ATP6 pathogenic variants reveals distinct regulatory consequencesfrom the co-translational quality control of mitochondrial protein synthesis.

Pathogenic variants that disrupt human mitochondrial protein synthesis are associated with a clinically heterogenous group of diseases. Despite an impairment in oxidative phosphorylation being a common phenotype, the underlying molecular pathogenesis is more complex than simply a bioenergetic deficiency. Currently, we have limited mechanistic understanding on the scope by which a primary defect in mitochondrial protein synthesis contributes to organelle dysfunction. Since the proteins encoded in the mitochondrial genome are hydrophobic and need co-translational insertion into a lipid bilayer, responsive quality control mechanisms are required to resolve aberrations that arise with the synthesis of truncated and misfolded proteins. Here, we show that defects in the OXA1L-mediated insertion of MT-ATP6 nascent chains into the mitochondrial inner membrane are rapidly resolved by the AFG3L2 protease complex. Using pathogenic MT-ATP6 variants, we then reveal discrete steps in this quality control mechanism and the differential functional consequences to mitochondrial gene expression. The inherent ability of a given cell type to recognize and resolve impairments in mitochondrial protein synthesis may in part contribute at the molecular level to the wide clinical spectrum of these disorders.

molecular biology↗