Required for cellulose microfibrils formation. Involved in cell wall assembly during cell elongation and cell plate maturation in cytokinesis. Required for secondary cell wall formation in the developing xylem. May cycle through different intracellular compartments, including plasma membrane. Endohydrolysis of (1->4)-beta-D-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans. Cell plate. Highly expressed in roots and stems, at intermediate levels in leaves and flowers, and at lower levels in siliques. Expressed in xylem (at protein level). Expressed during hypocotyl elongation in the dark. Glycosylated. N-glycosylation of KOR in the endoplasmic reticulum followed by N-glycan modifications in the Golgi are essential for catalytic activity. Plants are extremely dwarf and show severe abnormal morphology with incomplete cell walls, aberrant cell plates and multinucleated cells. Belongs to the glycosyl hydrolase 9 (cellulase E) family.