Writing in the June 8, 2023 edition of Cell, first author Kavita J. Rangan, PhD, a postdoctoral researcher in the lab of senior author Samara L. Reck-Peterson, PhD, a professor in the departments of Cellular and Molecular Medicine at UC San Diego School of Medicine and Cell and Developmental Biology at UC San Diego and an Investigator of the Howard Hughes Medical Institute, describe how opalescent inshore squid (Doryteuthis opalescens) employ RNA recoding to change amino acids at the protein level, improving the function of molecular motors that carry out diverse functions within cells in colder waters.RNA recoding allows organisms to edit genetic information from the genomic blueprint to create new proteins. The process is rare in humans but is common in soft-bodied cephalopods, such as D. opalescens, which makes seasonal spawning migrations along the coast of San Diego.
In the new study, Rangan and Reck-Peterson looked at changes to a pair of proteins in squid cells that serve as molecular motors transporting a variety of intracellular cargoes along cellular highways called microtubules. Specifically, the researchers focused on molecular motor proteins called kinesin and dynein, both of which are fundamental to transportation within all cells, including neurons. In humans, mutations in both motors are linked to neurodegenerative diseases.
Working with live squid hatchlings at Scripps Institution of Oceanography, Rangan found that recoding of kinesin increased in animals as they experienced colder ocean water temperatures. Rangan then recreated recoded kinesin proteins using recombinant DNA technology and biochemistry. She then measured the movement of single motor molecules using advanced light microscopy and found that the recoded kinesin motors functioned better at cold temperatures.The scientists also found that RNA recoding varied across tissues, generating new kinesin variants with distinct movement properties.
