Abstract: Signal transducer and activator of transcription 3 (STAT3) exists in the cytoplasm, nucleus, mitochondria, and mitochondria associated endoplasmic reticulum membranes, which is a signal transduction protein involved in various physiological processes such as cell proliferation, differentiation, migration, and immune regulation. This article provides an overview of the structures and types of STAT3 and the pathways through which STAT3 enters mitochondria, and elaborates on the regulatory effect of STAT3 on cellular homeostasis including the anti-apoptotic effect mediated by endoplasmic reticulum Ca2+ transport, the mechanism of action in maintaining mitochondrial function, and the regulatory mechanism on lipid synthesis and catabolism. Furthermore, this paper explores the regulatory mechanism of STAT3 on meat color from the perspective of regulating hematopoietic stem cells, skeletal muscle, mitochondrial homeostasis, and lipid synthesis and metabolism in order to provide a theoretical reference for improving meat color.

Key words: signal transducer and activator of transcription 3; mitochondrial homeostasis; myoglobin; free radicals; color stability