Differential incorporation of biotinylated polyamines by transglutaminase 2.
Polyamine incorporation or cross-linking of proteins, post-translational modifications mediated by transglutaminase 2 (TGase 2), have been implicated in a variety of physiological functions including cell adhesion, extracellular matrix formation and apoptosis. To better understand the intracellular regulation mechanism of TGase 2, the properties of biotinylated polyamines as substrates for determining in situ TGase activity were analyzed. We synthesized biotinylated spermine (BS), and compared the in vitro and in situ incorporation of BS with that of biotinylated pentylamine (BP), which is an artificial polyamine derivative. When measured in vitro, BP showed a significantly higher incorporation rate than BS. In contrast, in situ incorporation of both BS and BP was not detected even in TGase 2-overexpressed 293 cells. Cells exposed to high calcium showed a marked increase of BP incorporation but not of BS. These data indicate that the in situ activity of TGase 2 gives different results with different substrates, and suggest the possibility of overrepresentation of in situ TGase 2 activity when assayed with BP. Therefore, careful interpretation or evaluation of in situ TGase 2 activity may be required.
Jeon
Ju Hong
JH
Department of Biochemistry and Molecular Biology/Aging and Apoptosis Research Center (AARC), Seoul National University College of Medicine, 28 Yongon Dong, Chongno Gu, Seoul 110-799, South Korea.
Kim
Chai Wan
CW
Shin
Dong Myung
DM
Kim
Kyu il
Ki
Cho
Sung Yup
SY
Kwon
Joon Cheol
JC
Choi
Kyung Ho
KH
Kang
Heun Soo
HS
Kim
In Gyu
IG
D000588:Amines / Q000737:chemistry / Q000378:metabolism; D001710:Biotin / Q000737:chemistry / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D011073:Polyamines / Q000737:chemistry / Q000378:metabolism*; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D015203:Reproducibility of Results; D013096:Spermine / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D011503:Transglutaminases / Q000235:genetics / Q000378:metabolism*
D000588:Amines; D011073:Polyamines; D013096:Spermine; D001710:Biotin; C005264:n-amylamine; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins; D002118:Calcium