Human BBC3 (PUMA) knockout HeLa cell lysate

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

PUMA also known as BBC3 (Bcl-2-binding component-3) is a pro-apoptotic protein that plays important mechanical roles in promoting apoptosis. It has a mass of approximately 23 kDa. PUMA is expressed widely in various tissues including the lung liver and heart. The protein works mechanically by interacting with anti-apoptotic Bcl-2 family members releasing pro-apoptotic factors like Bax and Bak which engage mitochondria to trigger cell death.

Biological function summary

PUMA functions as a pivotal mediator of apoptosis in response to diverse stimuli such as DNA damage and oncogenic stress. As part of the Bcl-2 family PUMA does not typically form a complex with other proteins but functions directly by binding and neutralizing anti-apoptotic Bcl-2 family proteins. This action results in the release of caspase-activating factors from mitochondria essential for programmed cell death.

Pathways

Several cellular pathways incorporate PUMA to regulate apoptosis. PUMA is notably included in the p53 pathway where p53 transcriptionally activates PUMA following cellular stress or DNA damage. The presence of related proteins like Bax and Bim in the mitochondrial apoptotic pathway links these signals to the mitochondrial death machinery facilitating apoptosis.

Associated diseases and disorders

PUMA plays significant roles in cancer and neurodegenerative conditions. PUMA overexpression induces excessive cell death relevant in the pathology of neurodegenerative diseases. In cancer PUMA's interactions with proteins like p53 highlight its involvement in tumor suppression suggesting that dysregulation of PUMA expression can contribute to tumorigenesis when anti-apoptotic signals predominate potentially leading to chemoresistance.