Purification, Characterization, and Gene Expression of Rice Endo-β-N-Acetylglucosaminidase, Endo-Os

Bibliographic Details
Title: Purification, Characterization, and Gene Expression of Rice Endo-β-N-Acetylglucosaminidase, Endo-Os
Authors: Megumi Maeda, Naoko Okamoto, Norie Araki, Yoshinobu Kimura
Source: Frontiers in Plant Science, Vol 12 (2021)
Publisher Information: Frontiers Media S.A., 2021.
Publication Year: 2021
Collection: LCC:Plant culture
Subject Terms: endo-β-N-acetylglucosaminidase, free N-glycans, Oryza sativa, ER associated degradation, peptide:N-glycanase, Plant culture, SB1-1110
More Details: In the endoplasmic reticulum-associated degradation system of plant and animal cells, high-mannose type free N-glycans (HMT-FNGs) are produced from misfolded glycoproteins prior to proteasomal degradation, and two enzymes, cytosolic peptide:N-glycanase (cPNGase) and endo-β-N-acetylglucosaminidase (endo-β-GlcNAc-ase), are involved in the deglycosylation. Although the physiological functions of these FNGs in plant growth and development remain to be elucidated, detailed characterization of cPNGase and endo-β-GlcNAc-ase is required. In our previous work, we described the purification, characterization, and subcellular distribution of some plant endo-β-GlcNAc-ases and preliminarily reported the gene information of rice endo-β-GlcNAc-ase (Endo-Os). Furthermore, we analyzed the changes in gene expression of endo-β-GlcNAc-ase during tomato fruit maturation and constructed a mutant line of Arabidopsis thaliana, in which the two endo-β-GlcNAc-ase genes were knocked-out based on the Endo-Os gene. In this report, we describe the purification, characterization, amino acid sequence, and gene cloning of Endo-Os in detail. Purified Endo-Os, with an optimal pH of 6.5, showed high activity for high-mannose type N-glycans bearing the Manα1-2Manα1-3Manβ1 unit; this substrate specificity was almost the same as that of other plant endo-β-GlcNAc-ases, suggesting that Endo-Os plays a critical role in the production of HTM-FNGs in the cytosol. Electrospray ionization-mass spectrometry analysis of the tryptic peptides revealed 17 internal amino acid sequences, including the C terminus; the N-terminal sequence could not be identified due to chemical modification. These internal amino acid sequences were consistent with the amino acid sequence (UniProt ID: Q5W6R1) deduced from the Oryza sativa cDNA clone AK112067 (gene ID: Os05g0346500). Recombinant Endo-Os expressed in Escherichia coli using cDNA showed the same enzymatic properties as those of native Endo-Os.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1664-462X
Relation: https://www.frontiersin.org/articles/10.3389/fpls.2021.647684/full; https://doaj.org/toc/1664-462X
DOI: 10.3389/fpls.2021.647684
Access URL: https://doaj.org/article/2bf6eb38929144498ce3437baa782ac6
Accession Number: edsdoj.2bf6eb38929144498ce3437baa782ac6
Database: Directory of Open Access Journals
More Details
ISSN:1664462X
DOI:10.3389/fpls.2021.647684
Published in:Frontiers in Plant Science
Language:English