Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.
Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functiona...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2013-01-01
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| Series: | PLoS Genetics |
| Online Access: | http://europepmc.org/articles/PMC3749933?pdf=render |
| _version_ | 1817982868013449216 |
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| author | Lifeng Liu Keke Shang-Guan Baocai Zhang Xiangling Liu Meixian Yan Lanjun Zhang Yanyun Shi Mu Zhang Qian Qian Jiayang Li Yihua Zhou |
| author_facet | Lifeng Liu Keke Shang-Guan Baocai Zhang Xiangling Liu Meixian Yan Lanjun Zhang Yanyun Shi Mu Zhang Qian Qian Jiayang Li Yihua Zhou |
| author_sort | Lifeng Liu |
| collection | DOAJ |
| description | Cellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity. |
| first_indexed | 2024-04-13T23:25:47Z |
| format | Article |
| id | doaj.art-0b33677324f94f74959d67c24075eb59 |
| institution | Directory Open Access Journal |
| issn | 1553-7390 1553-7404 |
| language | English |
| last_indexed | 2024-04-13T23:25:47Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Genetics |
| spelling | doaj.art-0b33677324f94f74959d67c24075eb592022-12-22T02:25:03ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042013-01-0198e100370410.1371/journal.pgen.1003704Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils.Lifeng LiuKeke Shang-GuanBaocai ZhangXiangling LiuMeixian YanLanjun ZhangYanyun ShiMu ZhangQian QianJiayang LiYihua ZhouCellulose represents the most abundant biopolymer in nature and has great economic importance. Cellulose chains pack laterally into crystalline forms, stacking into a complicated crystallographic structure. However, the mechanism of cellulose crystallization is poorly understood. Here, via functional characterization, we report that Brittle Culm1 (BC1), a COBRA-like protein in rice, modifies cellulose crystallinity. BC1 was demonstrated to be a glycosylphosphatidylinositol (GPI) anchored protein and can be released into cell walls by removal of the GPI anchor. BC1 possesses a carbohydrate-binding module (CBM) at its N-terminus. In vitro binding assays showed that this CBM interacts specifically with crystalline cellulose, and several aromatic residues in this domain are essential for binding. It was further demonstrated that cell wall-localized BC1 via the CBM and GPI anchor is one functional form of BC1. X-ray diffraction (XRD) assays revealed that mutations in BC1 and knockdown of BC1 expression decrease the crystallite width of cellulose; overexpression of BC1 and the CBM-mutated BC1s caused varied crystallinity with results that were consistent with the in vitro binding assay. Moreover, interaction between the CBM and cellulose microfibrils was largely repressed when the cell wall residues were pre-stained with two cellulose dyes. Treating wild-type and bc1 seedlings with the dyes resulted in insensitive root growth responses in bc1 plants. Combined with the evidence that BC1 and three secondary wall cellulose synthases (CESAs) function in different steps of cellulose production as revealed by genetic analysis, we conclude that BC1 modulates cellulose assembly by interacting with cellulose and affecting microfibril crystallinity.http://europepmc.org/articles/PMC3749933?pdf=render |
| spellingShingle | Lifeng Liu Keke Shang-Guan Baocai Zhang Xiangling Liu Meixian Yan Lanjun Zhang Yanyun Shi Mu Zhang Qian Qian Jiayang Li Yihua Zhou Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils. PLoS Genetics |
| title | Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils. |
| title_full | Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils. |
| title_fullStr | Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils. |
| title_full_unstemmed | Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils. |
| title_short | Brittle Culm1, a COBRA-like protein, functions in cellulose assembly through binding cellulose microfibrils. |
| title_sort | brittle culm1 a cobra like protein functions in cellulose assembly through binding cellulose microfibrils |
| url | http://europepmc.org/articles/PMC3749933?pdf=render |
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