Title: Domain swaps of Arabidopsis secondary wall cellulose synthases to elucidate their class specificity

Abstract

Here, cellulose microfibrils are synthesized by membrane-embedded cellulose synthesis complexes (CSCs), currently modeled as hexamers of cellulose synthase (CESA) trimers. The three paralogous CESAs involved in secondary cell wall (SCW) cellulose biosynthesis in Arabidopsis (CESA4, CESA7, CESA8) are similar, but nonredundant, with all three isoforms required for assembly and function of the CSC. The molecular basis of protein–protein recognition among the isoforms is not well understood. To investigate the locations of the interfaces that are responsible for isoform recognition, we swapped three domains between the Arabidopsis CESAs required for SCW synthesis (CESA4, CESA7, and CESA8): N-terminus, central domain containing the catalytic core, and C-terminus. Chimeric genes with all pairwise permutations of the domains were tested for in vivo functionality within knockout mutant backgrounds of cesa4, cesa7, and cesa8. Immunoblotting with isoform-specific antibodies confirmed the anticipated protein expression in transgenic plants. The percent recovery of stem height and crystalline cellulose content was assayed, as compared to wild type, the mutant background lines, and other controls. Retention of the native central domain was sufficient for CESA8 chimeras to function, with neither its N-terminal nor C-terminal domains required. The C-terminal domain is required for class-specific function of CESA4 and CESA7, and CESA7 alsomore » requires its own N-terminus. Across all isoforms, the results indicate that the central domain, as well as the N- and C-terminal regions, contributes to class-specific function variously in Arabidopsis CESA4, CESA7, and CESA8.« less

Authors:

Hill, Jr, Joseph Lee ^[1]; Hill, Ashley Nicole ^[1]; Roberts, Alison W. ^[2]; Haigler, Candace H. ^[3]; Tien, Ming ^[1]

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+ Show Author Affiliations

1. Department of Biochemistry and Molecular Biology, The Center for Lignocellulose Structure and Formation, Pennsylvania State University, University Park Pennsylvania
2. Department of Biological Sciences, University of Rhode Island, Kingston Rhode Island
3. Department of Crop and Soil Sciences and Department of Plant and Microbial Biology, North Carolina State University, Raleigh North Carolina

Publication Date:

2018-07-10

Research Org.:

Energy Frontier Research Centers (EFRC), Washington, D.C. (United States). Center for Lignocellulose Structure and Formation (CLSF); Pennsylvania State Univ., University Park, PA (United States); North Carolina State University, Raleigh, NC (United States); Univ. of Rhode Island, Kingston, RI (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1459680

Alternate Identifier(s):

OSTI ID: 1459681; OSTI ID: 1470661; OSTI ID: 1617033

Grant/Contract Number:  

SC0001090

Resource Type:

Published Article

Journal Name:

Plant Direct

Additional Journal Information:

Journal Name: Plant Direct Journal Volume: 2 Journal Issue: 7; Journal ID: ISSN 2475-4455

Publisher:

Wiley and American Society of Plant Biologists and Society for Experimental Biology

Country of Publication:

United Kingdom

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; biofuels (including algae and biomass); bio-inspired; membrane; carbon sequestration; materials and chemistry by design; synthesis (self-assembly); Arabidopsis thaliana; cellulose synthase; chimera; class specificity; domain swap; protein interaction; secondary cell wall