Localization of transforming growth factor-beta 1 in mitochondria of murine heart and liver.
Using both electron microscopic immunohistochemistry and cell fractionation techniques, we show that transforming growth factor-beta 1 (TGF-beta 1) is found in mitochondria of rat and mouse cardiac myocytes and rat hepatocytes. Four different polyclonal antibodies, raised against various epitopes encompassing the mature portion of the TGF-beta 1 molecule as well as the pro-region of its precursor, were used for the electron microscopy studies. The localization of TGF-beta 1 in mitochondria was confirmed by detection of the native peptide in mitochondria isolated from rat heart and liver; the majority of native TGF-beta 1 found in liver homogenates was recovered in highly pure mitochondrial fractions. The functional role of TGF-beta in the mitochondrion is unknown at present.
Heine
U I
UI
Laboratory of Chemoprevention, National Cancer Institute, Bethesda, Maryland 20892.
Burmester
J K
JK
Flanders
K C
KC
Danielpour
D
D
Munoz
E F
EF
Roberts
A B
AB
Sporn
M B
MB
D000818:Animals; D002458:Cell Fractionation; D007150:Immunohistochemistry; D051379:Mice; D008929:Mitochondria, Heart / Q000737:chemistry*; D008930:Mitochondria, Liver / Q000737:chemistry*; D051381:Rats; D011919:Rats, Inbred Strains; D016212:Transforming Growth Factor beta / Q000032:analysis*
D016212:Transforming Growth Factor beta