The gene expression and bioinformatic analysis of choline trimethylamine-lyase (CutC) and its activating enzyme (CutD) for gut microbes and comparison with their TMA production levels

Latha Ramireddy; Hau-Yang Tsen; Yu-Chen Chiang; Chen Ying Hung; Fu-Chih Chen; Hsien-Tung Yen

doi:10.1016/j.crmicr.2021.100043

The gene expression and bioinformatic analysis of choline trimethylamine-lyase (CutC) and its activating enzyme (CutD) for gut microbes and comparison with their TMA production levels

Curr Res Microb Sci. 2021 Jun 17:2:100043. doi: 10.1016/j.crmicr.2021.100043. eCollection 2021 Dec.

Authors

Latha Ramireddy¹, Hau-Yang Tsen¹, Yu-Chen Chiang², Chen Ying Hung³, Fu-Chih Chen⁴, Hsien-Tung Yen^{3

4}

Affiliations

¹ Department of Food Science and Technology, Hung Kuang University, Shalu District, Taichung, Taiwan, R.O.C.
² Department of Food Nutrition and Health Biotechnology, Asia University, Wufeng, Taichung, Taiwan, ROC.
³ Department of Internal Medicine, Taipei Veterns General Hospital, Hsinchu Branch, Hsinchu, Taiwan.
⁴ Uni President Enterprises Corporation, Yongkang, Tainan, Taiwan.

Abstract

Recent studies revealed that some intestinal microorganisms anaerobically convert choline to trimethylamine (TMA) by choline TMA-lyase (cutC). TMA is further oxidized to trimethylamine-N-oxide (TMAO), by the liver enzyme flavin-dependent monooxygenase 3 (FMO3). TMA in the serum is correlated with the risk of cardiovascular disease and some other diseases in human. The objective of this study is to study the expression levels of cutC and its activating enzyme (cutD) gene for these microorganisms and their association with TMA production. In this study, we collected 20 TMA producing bacteria strains representing 20 species, and designed primers to evaluate their gene expression levels by reverse transcription quantitative PCR (RT-qPCR). In addition, TMA production was analyzed by UPLC-MS/MS. Results showed that gene expression levels of most individual strains were different when compared with the gene expression level of their glyceraldehyde-3 phosphate dehydrogenase (GAPDH) gene and the TMA production level of gut bacteria may not correlate with their cutC/cutD gene expression levels. Bioinformatic analysis of the CutC protein showed conserved choline binding site residues; cutD showed conserved S-adenosylmethionine (SAM) and two CX2-CX2-CX3 motifs. The present study reports that the TMA production level may not only depend on cutC/cutD gene expression. Other factors may need to be investigated.

Keywords: Bioinformatics; Choline TMA-lyase (cutC) gene; Gut microbiota; PCR Primers; Trimethylamine (TMA).