Interaction between Kringle and Growth-Factor-Like Domains in the Urokinase Molecule: Possible Role in Stimulation of Chemotaxis

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V. V. Stepanova¹, I. B. Beloglazova¹, Y. G. Gursky¹, R. S. Bibilashvily¹, Y. V. Parfyonova^1*, and V. A. Tkachuk^1,2

¹Russian Cardiology Research Center, Ministry of Health of Russian Federation, 3-ya Cherepkovskaya ul. 15a, 121552 Moscow, Russia; fax: (495) 414-6712; E-mail: yeparfyon@cardio.ru; irene@cardio.ru

²Faculty of Fundamental Medicine, Lomonosov Moscow State University, Lomonosovsky pr. 31/5, 119192 Moscow, Russia

^* To whom correspondence should be addressed.

Received July 12, 2007; Revision received September 24, 2007

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The results presented in this paper suggest the presence of an interaction between the kringle- and the growth-factor-like urokinase domains. This interaction regulates chemotactic properties of urokinase. We also show that interaction of urokinase with its “classical” receptor (uPAR) has a “permissive” effect on the interactions between the kringle domain and other targets on the cell surface. On the basis of our data we can suggest that uPAR serves as an “adaptor” for urokinase, and the binding of urokinase kringle domain to its receptor causes immediate activation of intracellular signaling and induction of cell migration.

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KEY WORDS: urokinase, kringle domain, urokinase receptor, intermolecular interactions, cellular migration

DOI: 10.1134/S0006297908030036

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