Biology subjects

Gogoi, J.

Publications and source records attributed to Gogoi, J..

3 recordsLinked to original sources

bioRxiv2026

Bacterial ancestry of the mitochondrial ATP exporter

Mitochondria originated through endosymbiosis of an Alphaproteobacterium within an Asgard archaeal host, with ATP export to the cytosol being a key driver for the organelle integration. The mitochondrial ATP/ADP carrier (AAC), a member of the SLC25 family, performs this critical function, whose evolutionary origin was not known due to the absence of any known prokaryotic homologues and was therefore termed a eukaryotic innovation. Here, using protein tertiary structure search combined with comprehensive sequence analyses, we identify conserved bacterial inner membrane transporters, CysZ and YihY, as putative homologues of mitochondrial AAC. CysZ and YihY are structurally similar to AAC, albeit with a circular permutation of one of the six transmembrane helices. Strikingly, we could identify the conserved MCF motif--a characteristic feature of the SLC25 family--in the bacterial sulfate transporter CysZ, suggesting a common ancestry. Together, our results identify a bacterial origin for the mitochondrial ATP exporter, thus resolving a long-standing question in mitochondrial evolution and a key step required for the emergence of eukaryotic cell complexity.

evolutionary biology↗

bioRxiv2021

Transferrin receptor 1-mediated iron uptake regulates bone mass in mice via osteoclast mitochondria and cytoskeleton

Increased intracellular iron spurs mitochondrial biogenesis and respiration to satisfy high-energy demand during osteoclast differentiation and bone-resorbing activities. Transferrin receptor 1 (TFR1) mediates cellular iron uptake through endocytosis of iron-loaded transferrin and its expression increases during osteoclast differentiation. Nonetheless, the precise functions of TFR1 and TFR1-mediated iron uptake in osteoclast biology and skeletal homeostasis remain incompletely understood. To investigate the role of TFR1 in osteoclast lineage cells, we conditionally deleted Tfr1 gene in myeloid precursors or mature osteoclasts by crossing Tfr1- floxed mice with LysM-Cre and Ctsk-Cre mice, respectively. Skeletal phenotyping by {micro}CT and histology unveiled that loss of Tfr1 in osteoclast progenitor cells resulted in a three-fold increase in trabecular bone mass in the long bones of 10-week old female but not male mice. Although high trabecular bone volume in long bones was seen in both male and female mice with deletion of Tfr1 in mature osteoclasts, this phenotype was more pronounced in female knockout mice. Mechanistically, disruption of Tfr1 expression attenuated mitochondrial metabolism and cytoskeletal organization in mature osteoclasts, leading to decreased bone resorption with no impact on osteoclastogenesis. These results indicate that Tfr1-mediated iron uptake is specifically required for osteoclast function and is indispensable for bone remodeling.

cell biology↗

bioRxiv2018

A discriminator code-based DTD surveillance ensures faithful glycine delivery for protein biosynthesis in bacteria

D-aminoacyl-tRNA deacylase (DTD) acts on achiral glycine, in addition to D-amino acids, attached to tRNA. We have recently shown that this activity enables DTD to clear non-cognate Gly-tRNAAla with 1000-fold higher efficiency than its activity on Gly-tRNAGly, indicating tRNA-based modulation of DTD (Pawar et al., 2017). Here, we show that tRNAs discriminator base predominantly accounts for this activity difference and is the key to selection by DTD. Accordingly, the uracil discriminator base, serving as a negative determinant, prevents Gly-tRNAGly misediting by DTD and this protection is augmented by EF-Tu. Intriguingly, eukaryotic DTD has inverted discriminator base specificity and uses only G3*U70 for tRNAGly/Ala discrimination. Moreover, DTD prevents alanine-to-glycine misincorporation in proteins rather than only recycling mischarged tRNAAla. Overall, the study reveals the unique co-evolution of DTD and discriminator base, \"reciprocally\" in Bacteria and Eukarya, and suggests DTDs strong selection pressure on bacterial tRNAGlys to retain a pyrimidine discriminator code.

biochemistry↗