Expression and localization of two β-carbonic anhydrases in Bienertia, a single-cell C₄ plant

verfasst von

Tho Nguyen, Nakyoung Lee, Fabian J. Frömling, Toni L. Meister, Jung Sun Kim, Sascha Offermann, Inhwan Hwang

Abstract

Carbonic anhydrases (CAs) are ubiquitous enzymes that catalyze reversibly both the hydration and dehydration reactions of CO₂ and HCO₃-, respectively. Higher plants contain many different isoforms of CAs that can be classified into α-, β- and γ-type subfamilies. β-type CAs play a key role in the CO₂-concentrating mechanism, thereby contributing to efficient photosynthesis in the C₄ plants in addition to many other biochemical reactions in plant metabolism. Here, we characterized at the molecular, cellular and biochemical levels two β-type CAs in Bienertia sinuspersici, a plant that operates a C₄ carbon concentrating mechanism within individual cells without the Kranz anatomy. These two β-type CAs (BsCAβs), named BsCAβ1 and BsCAβ2, in Bienertia were strongly induced along with maturation of leaves. Both BsCAβ1 and BsCAβ2 existed as a dimeric form in vivo but showed differential localization. BsCAβ2 was localized exclusively to the plasma membrane in Bienertia and when expressed heterologously in the C₃ Arabidopsis. In contrast, BsCAβ1 largely localized to the cytosol together with a portion to the plasma membrane (PM) in both plants. BsCAβ2 had two cysteine residues at the N-terminal region for palmitoylation and their substitution with serine residues led to a change in the localization from the plasma membrane (PM) to the cytosol. Thus, we propose that BsCAβ2 localizes to the PM using a lipid moiety added posttranslationally plays a role in conversion of cytosolic CO₂ into HCO₃- as part of the CO₂-concentrating mechanism, thereby contributing to the single-cell C₄ photosynthesis in Bienertia.

Organisationseinheit(en)

Institut für Botanik

Externe Organisation(en)

Pohang University of Science and Technology
The Karlsruhe Municipal Hospital
Universität Hamburg
Bernhard-Nocht-Institut für Tropenmedizin (BNITM)
Deutsches Zentrum für Infektionsforschung e. V. (DZIF) Standort Hamburg - Lübeck - Borstel - Riems
Rural Development Administration

Typ

Artikel

Journal

Frontiers in Plant Science

Band

15

ISSN

1664-462X

Publikationsdatum

16.01.2025

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Pflanzenkunde

Elektronische Version(en)

https://doi.org/10.3389/fpls.2024.1506375 (Zugang: Offen)