CHITINASE-LIKE1/POM-POM1 and Its Homolog CTL2 Are Glucan-Interacting Proteins Important for Cellulose Biosynthesis in Arabidopsis[W][OA]
| Autor: | Chris Somerville, Kian Hématy, Clara Sánchez-Rodríguez, Friederike Saxe, Lutz Neumetzler, Markus Rüggeberg, Marie-Theres Hauser, Arun Sampathkumar, Stefan Bauer, Cornelia Konlechner, Ingo Burgert, Ernst Aichinger, Ana B. Ibáñez, Vera Vodermaier, Staffan Persson |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Glycoside Hydrolases
Arabidopsis Plant Science Biology Polysaccharide Cell wall chemistry.chemical_compound Cell Wall Polysaccharides Glycoside hydrolase Endomembrane system Cellulose Glucans Research Articles Glucan chemistry.chemical_classification Arabidopsis Proteins Chitinases Cell Biology Plants Genetically Modified Xyloglucan chemistry Biochemistry Microfibrils Microfibril |
| Zdroj: | Plant Cell |
| Popis: | Plant cells are encased by a cellulose-containing wall that is essential for plant morphogenesis. Cellulose consists of β-1,4-linked glucan chains assembled into paracrystalline microfibrils that are synthesized by plasma membrane–located cellulose synthase (CESA) complexes. Associations with hemicelluloses are important for microfibril spacing and for maintaining cell wall tensile strength. Several components associated with cellulose synthesis have been identified; however, the biological functions for many of them remain elusive. We show that the chitinase-like (CTL) proteins, CTL1/POM1 and CTL2, are functionally equivalent, affect cellulose biosynthesis, and are likely to play a key role in establishing interactions between cellulose microfibrils and hemicelluloses. CTL1/POM1 coincided with CESAs in the endomembrane system and was secreted to the apoplast. The movement of CESAs was compromised in ctl1/pom1 mutant seedlings, and the cellulose content and xyloglucan structures were altered. X-ray analysis revealed reduced crystalline cellulose content in ctl1 ctl2 double mutants, suggesting that the CTLs cooperatively affect assembly of the glucan chains, which may affect interactions between hemicelluloses and cellulose. Consistent with this hypothesis, both CTLs bound glucan-based polymers in vitro. We propose that the apoplastic CTLs regulate cellulose assembly and interaction with hemicelluloses via binding to emerging cellulose microfibrils. |
| Databáze: | OpenAIRE |
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