The mammalian target of rapamycin, also known as mTOR, is a protein kinase that is involved in many cellular processes. The spelling of this word can be explained using the International Phonetic Alphabet (IPA), which represents the sounds of spoken language. The word "mammalian" is pronounced /məˈmeɪliən/ (muh-MEY-lee-uhn), with stress on the second syllable. "Target" is pronounced /ˈtɑːrɡɪt/ (TAR-git) with stress on the first syllable. "Rapamycin" is pronounced /rəˈpæmɪsɪn/ (ruh-PAM-uh-sin), with stress on the second syllable.
Mammalian target of rapamycin (mTOR) is a protein kinase that plays a crucial role in regulating various cellular processes, including cell growth, proliferation, metabolism, and survival. It is found in many eukaryotic organisms, including mammals, where it serves as a central regulator of growth and metabolism.
mTOR is a large protein complex that exists in two distinct complexes: mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2). Each complex has a unique set of proteins and functions, although they also exhibit some overlapping roles.
mTORC1 primarily regulates cell growth and metabolism in response to changes in nutrient availability, energy levels, and growth factors. It integrates signals from insulin, growth factors, and amino acids to promote protein synthesis, lipid synthesis, and inhibit autophagy, a cellular recycling process. Dysregulation of mTORC1 is associated with various diseases, including cancer, metabolic disorders, and neurodegenerative diseases.
mTORC2, on the other hand, plays a role in regulating cell survival, cytoskeletal organization, and cell migration. It is less understood compared to mTORC1, but recent studies have suggested its involvement in insulin signaling, cell growth, and metabolic regulation.
The discovery and characterization of mTOR have paved the way for the development of rapamycin and its derivatives, which are potent inhibitors of mTOR signaling. These drugs are used in various medical settings, such as immunosuppression in organ transplantation, cancer treatment, and combating age-related diseases.