Biology subjects

Mano, S.

Publications and source records attributed to Mano, S..

3 recordsLinked to original sources

bioRxiv2023

Cytosolic heme metabolism by alternative localization of heme oxygenase 1 in plant cells

Heme, an organometallic molecule, is widely engaged in oxygen transport, electron delivery, enzymatic reactions, and signal transduction. Additionally, heme serves as a precursor to phytochromobilin, the chromophore of plant phytochrome. Heme oxygenase (HO) initiates the first committed step in heme metabolism. Our transcription start site-sequencing (TSS-seq) revealed that HO1 in Arabidopsis thaliana and Oryza sativa (rice) has two TSSs, producing long (HO1L) and short (HO1S) transcripts, with or without an intact N-terminal plastid transit peptide. HO1L and HO1S products localize in plastids and the cytosol, respectively. In Arabidopsis, HO1L is prevalent in light-exposed shoots, while HO1S is clearly detected in roots and etiolated seedlings. During de-etiolation and early development, HO1L ratio gradually rises and HO1S ratio decreases. Light perception via phytochrome and cryptochrome elevates HO1L ratio and reduce HO1S ratio through the functioning of HY5 and HYH transcription factors, and the suppression of DET1, E3 ubiquitin ligase COP1, and PIFs transcription factors. As expected, HO1L product was able to complement the HO1-deficient mutant gun2 (hy1), but surprisingly, HO1S expression could also restore the short hypocotyl phenotype and high pigment content, and make the mutant recover from the gun phenotype. This indicates the formation of functional holo-phytochrome within these lines. Our work highlights the presence of a cytosolic pathway for heme metabolism, especially during etiolation and early development. Furthermore, it supports the hypothesis that a mobile heme signal is involved in the mediation of retrograde signaling from the chloroplast. Significance StatementIn this research, through both TSS-seq and CAGE-seq, we discovered that the HO1 (GUN2 or HY1) gene in both Arabidopsis and rice has two TSSs, generating HO1L and HO1S transcripts. We reveal that the HO1 TSS regulation pathway is the same as the light signaling pathway. Significantly, our study identifies that a cytosolic heme metabolism pathway is existent in plant cells.

plant biology↗

bioRxiv2021

Remodeling of organelles and microtubules during spermiogenesis in the liverwort Marchantia polymorpha

Gametogenesis is an essential biological event for sexual reproduction in various organisms. Bryophytes and some other plants employ motile sperms (spermatozoids) as male gametes, which self-locomote to the egg cells to accomplish fertilization. Spermatozoids of bryophytes harbor distinctive morphological characteristics, including the cell body with a helical slender shape and two motile flagella at the anterior edge. During transformation from a spermatid to spermatozoid (spermiogenesis), the shape and cellular contents of spermatids are dynamically reorganized. However, how each organelle is reorganized during plant spermiogenesis remains obscure. In this study, we classified the developmental processes during spermiogenesis in the liverwort Marchantia polymorpha according to cellular and nuclear shapes and flagella development. We then examined the remodeling of microtubules and reorganization of endomembrane organelles during spermiogenesis. The results indicate that the state of post-translational modification of tubulin is dynamically changed during the formation of the flagella and spline, and the plasma membrane and endomembrane organelles are drastically reorganized in a precisely regulated manner during spermiogenesis. These findings are expected to provide useful indexes to classify developmental and subcellular processes of spermiogenesis in bryophytes. Summary statementWe classified developmental processes of spermatozoids into 1 + 5 stages and characterized remodeling of organelles and microtubules during spermiogenesis in the liverwort Marchantia polymorpha.

plant biology↗

bioRxiv2018

Alopecia areata susceptibility variant identified by MHC risk haplotype sequencing reproduces symptomatic patched hair loss in mice

BackgroundAlopecia areata (AA) is a highly heritable multifactorial and complex disease. However, no convincing susceptibility gene has yet been pinpointed in the major histocompatibility complex (MHC), a region in the human genome known to be associated with AA as compared to other regions.\n\nResultsBy sequencing MHC risk haplotypes, we identified a variant (rs142986308, p.Arg587Trp) in the coiled-coil alpha-helical rod protein 1 (CCHCR1) gene as the only non-synonymous variant in the AA risk haplotype. Using CRISPR/Cas9 for allele-specific genome editing, we then phenocopied AA symptomatic patched hair loss in mice engineered to carry the Cchcr1 risk allele. Skin biopsies of these alopecic mice showed strong up-regulation of hair-related genes, including hair keratin and keratin-associated proteins (KRTAPs). Using transcriptomics findings, we further identified CCHCR1 as a novel component of hair shafts and cuticles in areas where the engineered alopecic mice displayed fragile and impaired hair.\n\nConclusionsThese results suggest an alternative mechanism for the aetiology of AA based on aberrant keratinization, in addition to generally well-known autoimmune events.

genomics↗