Identification of a Region of the Polypeptide Chain of Na,K-ATPase α-Subunit Interacting with 67-kDa Melittin-Like Protein

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Yu. V. Kamanina^1,2, E. A. Klimanova^1,2, E. A. Dergousova^1,2, I. Yu. Petrushanko², and O. D. Lopina^1*

¹Lomonosov Moscow State University, Department of Biochemistry, School of Biology, 119991 Moscow, Russia; fax: +7 (495) 939-3955; E-mail: od_lopina@mail.ru

²Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia

^* To whom correspondence should be addressed.

Received June 25, 2015; Revision received July 6, 2015

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It was shown earlier that a 67-kDa protein purified from mouse kidney using polyclonal antibodies against melittin (a peptide from bee venom) interacted with Na,K-ATPase from rabbit kidney. In this study, a 43-kDa proteolytic fragment of Na,K-ATPase α-subunit interacting with the 67-kDa melittin-like protein was found. The α-subunit was hydrolyzed by trypsin in the presence of 0.5 mM ouabain (E2-conformation of Na,K-ATPase). A proteolytic fragment interacting with the 67-kDa melittin-like protein that was identified by mass-spectrometry is a region of the cytoplasmic domain of Na,K-ATPase α-subunit located between amino acid residues 591 and 775. The fragment includes a conservative DPPRA motif that occurs in many P-type ATPases. It was shown earlier that this motif of H,K-ATPase from gastric mucosa binds to melittin. We suggest that namely this motif of P-type ATPases is able to interact with proteins containing melittin-like modules.

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KEY WORDS: Na,K-ATPase, melittin-like proteins, protein–protein interactions

DOI: 10.1134/S000629791603007X

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