Serine/threonine-protein kinase TOR (IPR026683)

Short name: TOR

Overlapping homologous superfamilies


Family relationships



This entry represents the serine/threonine-protein kinase TOR (target of rapamycin), which was first identified by mutations in yeast that confer resistance to the growth inhibitory properties of rapamycin [PMID: 1715094]. TOR proteins are structurally and functionally conserved in all eukaryotes examined. However, yeasts contain two Tor proteins (Tor1 and Tor2), while higher eukaryotes such as humans possess a single TOR protein [PMID: 26028537]. They are central regulators of cellular metabolism, growth and survival in response environmental signals [PMID: 8741837, PMID: 11096119, PMID: 12150925].

In budding yeast, the Tor2 protein exists in two distinct multi-component complexes, TORC1 and TORC2. TORC1 regulates cell growth by regulating many growth-related processes and is rapamycin sensitive, while TROC2 regulates the cell cytoskeleton and is rapamycin insensitive. Budding yeast TORC1 consists of either Tor1 or Tor2 in complex with Kog1, Lst8 and Tco89, while TORC2 is composed of Avo1, Avo2, Tsc11, Lst8, Bit61, Slm, Slm2 and Tor2 [PMID: 26700129, PMID: 15689497]. In both yeast and mammals, FKBP12-rapamycin binds to Tor (Tor1, Tor2, or mTOR) in TORC1, but not to Tor (Tor2 or mTOR) in TORC2. It has been suggested that the architecture of TORC2 or its unique composition might be responsible for the observed rapamycin resistance [PMID: 26028537].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004674 protein serine/threonine kinase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.