KATO Lab Research

Microbial rhodopsins

Most animals, from simple, single-celled microbes to large mammals like humasn, receive light information through rhodopsin family proteins. Rhodopsins form a large superfamily of seven-transmembrane proteins, categorized into type I (microbial) and type II (animal) based on their diverse sequences and functions. Recently, ion channel and ion pump rhodopsins have attracted broad attentions because of their remarkable utility to be used as a genetic toolkit to modulate neuronal activity with light (=optogenetics). We are studying these microbial rhodopsins using structural, biophysical, biochemical, and electrophysiological techniques to better understand their structure-function relationship.

Microbial rhodopsins

GPCRs and their effectors

G protein-coupled receptors (GPCRs) are the largest superfamily of membrane receptors that human genome encodes more than 800 GPCRs. These receptors regulate virtually every aspect of human physiology including vision, olfaction, pain, immunity, neurotransmission, cardiovascular function, and they have been a major drug target for drug development (approximately 30% of marketed drugs target GPCRs). To better understand the molecular mechanisms underlying GPCR signaling, we are studying GPCRs and their effector molecules (e.g. G proteins and arrestins) using structural, biophysical, and biochemical techniques.

GPCRs and their effectors

Engineering

A deep understanding of structure-function relationships in proteins enables us to design novel protein tools with modified properties and small molecules and peptides that regulate protein functions and signaling pathways. Currently our lab is especially interested in structure-guided engineering of novel optogenetics tools and GPCR ligands and modulators. Through a broad international collaboration, we have previously developed several new optogenetics tools (e.g. C1C2GA, FLASH, ChRmine).