FKBP12-rapamycin-associated protein or mammalian target of rapamycin (FRAP/mTOR) localization in the endoplasmic reticulum and the Golgi apparatus.
FKBP12-rapamycin-associated protein (FRAP) or mammalian target of rapamycin (mTOR) and its effector proteins form a critical signaling pathway that regulates eukaryotic cell growth and proliferation. Although the protein components in this pathway have begun to be identified, little is known about their subcellular localization or the physiological significance of their localization. By immunofluorescence, we find that both endogenous and recombinant FRAP/mTOR proteins show localization predominantly in the endoplasmic reticulum (ER) and the Golgi apparatus. Consistent with this finding, FRAP/mTOR is cofractionated with calnexin, an ER marker protein. Biochemical characterization suggests that FRAP/mTOR is a peripheral ER/Golgi protein with tight membrane association. Finally, we have identified domains of FRAP/mTOR which may mediate its association with the ER and the Golgi apparatus.
Molecular Cell Biology Graduate Program, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Ryan M
RM
Drenan
Xiangyu
X
Liu
Paula G
PG
Bertram
X F Steven
XF
Zheng
D000818:Animals; D002352:Carrier Proteins; D004721:Endoplasmic Reticulum / Q000502:physiology*; D006056:Golgi Apparatus / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D008322:Mammals; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000032:analysis / Q000502:physiology*; D011494:Protein Kinases / Q000032:analysis / Q000502:physiology*; D011994:Recombinant Proteins / Q000032:analysis / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases; D022061:Tacrolimus Binding Protein 1A / Q000032:analysis / Q000502:physiology*; D014162:Transfection
D002352:Carrier Proteins; D011994:Recombinant Proteins; D011494:Protein Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D022061:Tacrolimus Binding Protein 1A