Related Experiment Video
Updated: Jun 19, 2026

A Scalable, Cell-Based Method for the Functional Assessment of Ube3a Variants
Published on: October 10, 2022
Human UDP-glucuronosyltransferase UGT2A2: cDNA construction, expression, and functional characterization in
Nina Sneitz1, Michael H Court, Xiuling Zhang
1Centre for Drug Research, Faculty of Pharmacy, University of Helsinki, Finland.
Objectives:
Characterize the expression and glucuronidation activities of the human uridine 5'-diphospho (UDP)-glucuronosyltransferase (UGT) 2A2.
Method:
UGT2A1 was cloned from nasal mucosa mRNA. Synthetic cDNA for UGT2A2 was constructed assuming exon sharing between UGT2A1 and UGT2A2 (Mackenzie et al., Pharmacogenetics and Genomics 2005, 15:677-685). Exon 1 of UGT2A2 was amplified from genomic DNA and combined with exons 2-6 of UGT2A1. UGT2A3 was cloned from liver mRNA. Quantitative reverse-transcribed-PCR (RT-PCR) was used to evaluate the expression of all the three UGTs of subfamily 2A in different tissues. Recombinant UGT2A1, UGT2A2 and UGT2A3 were expressed in baculovirus-infected insect cells and analyzed for glucuronidation activity towards different substrates.
Results:
DNA sequencing of RT-PCR products from human nasal mucosa mRNA, confirmed exon sharing between UGT2A1 and UGT2A2. In addition, it indicated that the N-terminal signal peptide sequence of UGT2A2 is the longest among the human UGTs. Quantitative RT-PCR revealed that both UGT2A1 and UGT2A2 are mainly expressed in the nasal mucosa, and that their expression level in fetal samples was much higher than in adults. Activity assays with recombinant UGTs 2A1-2A3 showed broad substrate selectivity for UGT2A1 and UGT2A2. Although glucuronidation rates and substrate affinities were mostly higher in UGT2A1, the Km values for UDP-glucuronic acid were similar in both UGTs. In addition, there were regioselectivity differences between the two UGTs and, with a few substrates, particularly ethinylestradiol, the activity of UGT2A2 was higher.
Conclusion:
UGT2A2 is mainly expressed in the nasal mucosa and it has glucuronidation activity towards several different endobiotic and xenobiotic substrates.
Related Concept Videos
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Phase II Reactions: Glucuronidation
Glucose Transporters
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Drug Metabolism: Phase II Reactions
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
