Susan Golden

Susan Golden ( Stephens; born 1957) is an American professor of molecular biology known for her research in circadian rhythms. She is a faculty member at UC San Diego (2008-present).

Early life and education Golden was born in Pine Bluff, Arkansas in 1957. She attended the local public high school, where she was involved with the marching band and school newspaper. She was accepted to the Mississippi University for Women in 1976 as a journalism major, but soon switched her studies to major in biology and minor in chemistry.

Golden graduated from MUW in two years, after which she was offered a position in the first cohort of trainees in a NIH-financed doctoral program in genetics at the University of Missouri. During her graduate program, Golden met James Golden, a fellow doctoral student. They later married in 1979. At the University of Missouri, Golden researched the protein makeup of the photosynthetic center in cyanobacteria, work she continued when she moved to the University of Chicago in 1983 as a postdoctoral research fellow.

Research contributions Early work Golden began her graduate career with Louis A. Sherman, using genetic tools to research the proteins in photosynthetic complexes of the cyanobacteria Synechoccus elongatus. Golden was the first to demonstrate that a mutant allele of the psbA gene is sufficient to confer herbicide resistance in cyanobacteria. These findings demonstrated that genetic manipulation of cyanobacteria was relatively simple, opening up S. elongatus as a model organism for future genetic experiments. This finding led her to investigate more generally how light influences expression of photosynthetic genes in the organism and contributed to understanding bacterial responses to environmental input. This line of inquiry necessitated the development of a technique for visualizing changes in gene expression in living organisms. During her time as a professor at the Texas A&M, Golden attempted to solve this problem by attaching a luciferase gene to the promoters of the cyanobacterial genes of interest and viewing the colonies with a night vision scope. This technique drew the interest of chronobiologist Carl H. Johnson, with whom Golden would collaborate and eventually discover the KaiABC complex . the only model organism for a prokaryotic circadian clock.

The kai protein circadian system S. elongatus has a circadian clock with an oscillator based only on three proteins: KaiA, KaiB, and KaiC. Circadium rhythm is generated based on KaiC phosphorylation and dephosphorylation. Light transmits energy and information to the cyanobacteria, affecting transcriptional regulation of the circadium clock. This 24-hour rhythm can be recreated in vitro with the addition of ATP. The ratio of ATP/ADP fluctuates during the course of the day, and is sensed by KaiC, which phosphorylates or de-phosphorylates based on this signal.

Current research Metabolic engineering After moving to UC San Diego in 2008, Susan Golden's research converged with that of her husband, James Golden, to investigate biofuels.

In 2016, Golden and colleagues manually curated a model of metabolism in S. elongatus, indicating the importance of a linear tricarboxylic acid cycle (TCA) metabolic pathway and potential modifications for bio-industrial application.

Honors, awards, and membership National Science Foundation Presidential Young Investigator Award, 1989 - 1995 Fellow of the American Academy of Microbiology, elected in 2000 Texas A&M Distinguished Professor, 2003 Member of the Faculty of 1000 Biology, 2008 - 2015 UC San Diego Distinguished Professor and Chancellor’s Associates Chair in Molecular Biology, 2008–present Member of the National Academy of Sciences, elected in 2010 Howard Hughes Medical Institute Professor, 2014–2024 Aschoff and Honma Prize for Biological Rhythm Research, 2018 Elected to the American Academy of Microbiology Board of Governors, 2019

Selected publications