This entry represents a glycosyltransferase-like domain found in alkaline ceramidase TOD1 and the probable hexosyltransferase MUCI70 from Arabidopsis. MUCI70 is a predicted glycosyltransferase essential for the accumulation of seed mucilage, a gelatinous wall rich in unbranched rhamnogalacturonan I (RG I), and for shaping the surface morphology of seeds [1,2]. TOD1 is an endoplasmic reticulum ceramidase that catalyses the hydrolysis of ceramides into sphingosine and free fatty acids at alkaline pH (e.g. pH 9.5) [3,4].

1: Identification of Key Enzymes for Pectin Synthesis in Seed Mucilage. Voiniciuc C, Engle KA, Gunl M, Dieluweit S, Schmidt MH, Yang JY, Moremen KW, Mohnen D, Usadel B; Plant Physiol. 2018;178:1045-1064. PMID:30228108

2: Natural Variation Reveals a Key Role for Rhamnogalacturonan I in Seed Outer Mucilage and Underlying Genes. Fabrissin I, Cueff G, Berger A, Granier F, Salle C, Poulain D, Ralet MC, North HM; Plant Physiol. 2019;181:1498-1518. PMID:31591153

3: The Arabidopsis alkaline ceramidase TOD1 is a key turgor pressure regulator in plant cells. Chen LY, Shi DQ, Zhang WJ, Tang ZS, Liu J, Yang WC; Nat Commun. 2015;6:6030. PMID:25591940

4: Turgor regulation defect 1 proteins play a conserved role in pollen tube reproductive innovation of the angiosperms. Ke CJ, Lin XJ, Zhang BY, Chen LY; Plant J. 2021;106:1356-1365. PMID:33735469