Epitranscriptomic N-6-Methyladenosine Modification Is Required for Direct Lineage Reprogramming into Neurons
ACS CHEMICAL BIOLOGY
Authors: Choi, Hwan; Baek, Soonbong; Cho, Byounggook; Kim, Siyoung; Kim, Junyeop; Chang, Yujung; Shin, Jaein; Kim, Jongpil
Abstract
N-6-methyladenosine (m(6)A), a conserved epitranscriptomic modification of eukaryotic mRNA (mRNA), plays a critical role in a variety of biological processes. Here, we report that m(6)A modification plays a key role in governing direct lineage reprogramming into induced neuronal cells (iNs). We found that m(6)A modification is required for the remodeling of specific mRNAs required for the neuronal direct conversion. Inhibition of m(6)A methylation by Mettl3 knockdown decreased the efficiency of direct lineage reprogramming, whereas increased m(6)A methylation by Mettl3 overexpression increased the efficiency of iN generation. Moreover, we found that transcription factor Btg2 is a functional target of m(6)A modification for efficient iN generation. Taken together, our results suggest the importance of establishing epitranscriptomic remodeling for the cell fate conversion into iNs.
Engineering an Alcohol-Forming Fatty Acyl-CoA Reductase for Aldehyde and Hydrocarbon Biosynthesis inSaccharomyces cerevisiae
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
Authors: Foo, Jee Loon; Rasouliha, Bahareh Haji; Susanto, Adelia Vicanatalita; Leong, Susanna Su Jan; Chang, Matthew Wook
Abstract
Aldehydes are a class of highly versatile chemicals that can undergo a wide range of chemical reactions and are in high demand as starting materials for chemical manufacturing. Biologically, fatty aldehydes can be produced from fatty acyl-CoA by the action of fatty acyl-CoA reductases. The aldehydes produced can be further converted enzymatically to other valuable derivatives. Thus, metabolic engineering of microorganisms for biosynthesizing aldehydes and their derivatives could provide an economical and sustainable platform for key aldehyde precursor production and subsequent conversion to various value-added chemicals.Saccharomyces cerevisiaeis an excellent host for this purpose because it is a robust organism that has been used extensively for industrial biochemical production. However, fatty acyl-CoA-dependent aldehyde-forming enzymes expressed inS. cerevisiaethus far have extremely low activities, hence limiting direct utilization of fatty acyl-CoA as substrate for aldehyde biosynthesis. Toward overcoming this challenge, we successfully engineered an alcohol-forming fatty acyl-CoA reductase for aldehyde production through rational design. We further improved aldehyde production through strain engineering by deleting competing pathways and increasing substrate availability. Subsequently, we demonstrated alkane and alkene production as one of the many possible applications of the aldehyde-producing strain. Overall, by protein engineering of a fatty acyl-CoA reductase to alter its activity and metabolic engineering ofS. cerevisiae, we generated strains with the highest reported cytosolic aliphatic aldehyde and alkane/alkene production to date inS. cerevisiaefrom fatty acyl-CoA.