Probable UDP-N-acetylglucosamine--peptide N-acetylglucosaminyltransferase SPINDLY

UniProtKB accession:  Q96301

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Probable O-linked N-acetylglucosamine transferase (OGT) involved in various processes such as gibberellin (GA) signaling pathway and circadian clock. OGTs catalyze the addition of nucleotide-activated sugars directly onto the polypeptide through O-glycosidic linkage with the hydroxyl of serine or threonine. Probably acts by adding O-linked sugars to yet unknown proteins. Acts as a repressor of GA signaling pathway to inhibit hypocotyl elongation. Functions with GIGANTEA (GI) in pathways controlling flowering, circadian cotyledon movements and hypocotyl elongation. Acts as a light-regulated promoter of elongation via its interaction with GI. Acts as an activator of cytokinin signaling. Required with SEC for gamete and seed development (PubMed:12136030). Its OGT activity has been proved in vitro but not in vivo (Ref.5, PubMed:11457967, PubMed:12136030, PubMed:15155885, PubMed:15608330, PubMed:8799194). Possesses O-fucosyltransferase activity on specific serine and threonine residues (PubMed:28244988). Mediates O-fucosylation of the DELLA protein RGA, a repressor of the GA signaling pathway (PubMed:28244988). O-fucosylation enhances RGA activity by promoting RGA binding to key transcription factors in brassinosteroid and light-signaling pathways (PubMed:28244988). Regulates root hair patterning upstream of the transcription factor WER, independently of DELLA proteins and GA signaling (PubMed:32928908). Involved in abscisic acid (ABA) signaling partly through functional ABAR (PubMed:34712252). Mediates O-fucosylation of CPN20 that may depress ABA responses during seed germination and seedling development (PubMed:34712252). Involved in the modulation of the pace of the circadian clock by mediating O-fucosylation of APRR5, one of the core circadian clock components (PubMed:31899321). O-fucosylation promotes APRR5 proteolysis (PubMed:31899321).