| Autor: |
Nery, Flávia C., Bressan, Gustavo C., Alborghetti, Marcos R., Passos, Dario O., Kuniyoshi, Taís M., Ramos, Carlos H.I., Oyama, Jr., Sergio, Kobarg, Jörg |
| Předmět: |
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| Zdroj: |
Biological Chemistry; May2006, Vol. 387 Issue 5, p577-582, 6p, 1 Black and White Photograph, 1 Diagram, 1 Graph |
| Abstrakt: |
Ki-1/57 is a 57-kDa cytoplasmic and nuclear protein associated with protein kinase activity and is hyper-phosphorylated on Ser/Thr residues upon cellular activation. In previous studies we identified the receptor of activated kinase-1 (RACK1), a signaling adaptor protein that binds activated PKC, as a protein that interacts with Ki-1/57. Here we demonstrate that the far-UV circular dichroism spectrum of the WD repeat-containing RACK1 protein shows an unusual positive ellipticity at 229 nm, which in other proteins of the WD family has been attributed to surface tryptophans that are quenchable by N-bromosuccinimide (NBS). As well as NBS, in vitro binding of 6×His-Ki-1/57(122–413) and 6×His-Ki-1/57(264–413) can also quench the positive ellipticity of the RACK1 spectrum. We generated a model of RACK1 by homology modeling using a G protein β subunit as template. Our model suggests the family-typical seven-bladed β-propeller, with an aromatic cluster around the central tunnel that contains four Trp residues (17, 83, 150, 170), which are likely involved in the interaction with Ki-1/57. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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