Project summary The purpose of this supplement is to provide additional time for the completion of the NRSA individual fellowship titled “Alcohol-induced skeletal muscle dysregulation in SIV/HIV: Mitochondrial-mediated mechanisms”, F32AA027982 after significant disruption due to the COVID-19 pandemic. At-risk alcohol use among people living with HIV (PLWH) is nearly twice that in the general population. Chronic at-risk alcohol use and HIV/SIV are independently associated with metabolic comorbidities including skeletal muscle (SKM) dysfunction. Based on our published and preliminary data, the global hypothesis of this work is that decreased peroxisome proliferator activated receptor gamma coactivator (PGC)-1β underlies chronic binge alcohol (CBA)-mediated decreases in mitochondrial biogenesis and function in SKM of SIV+ female rhesus macaques and that PGC-1β is a potential therapeutic target to improve mitochondrial homeostasis. Data generated will provide a more comprehensive molecular understanding of mitochondrial dysfunction in the context of HIV and alcohol and will provide a foundation for future mechanistic and translational studies.