التفاصيل البيبلوغرافية
العنوان: |
Predicted alterations in tertiary structure of the N-terminus of Na+/K+-ATPase α-subunit caused by phosphorylation or acidic replacement of the PKC phosphorylation site Ser-23. |
المؤلفون: |
Brandt, Wolfgang, Anders, Alexander, Vasilets, Larisa |
المصدر: |
Cell Biochemistry & Biophysics; Oct2002, Vol. 37 Issue 2, p83-95, 13p |
مستخلص: |
The protein kinase C (PKC)-mediated phosphorylation of the Na+/K+-ATPase α-subunit has been shown to play an important role in regulation of the Na+/K+-ATPase activity. In the rat α1-subunit, phosphorylation occurs at Ser-23 and results in inhibition of the transport function of the Na+/K+-ATPase, which is mimicked by replacing the Ser-23 by the negatively charged glutamic acid or by aspartic acid. Using comparative molecular modeling, we investigated whether phosphorylation or acidic replacement at position 23 causes a dramatic change in the molecular electrostatic potential at position 23 as a result of insertion of a negative charge of the phosphoryl group or Glu per se, or whether, alternatively, the modification causes larger-scale conformational changes in the N-terminus of the α-subunit. The results predict a considerable conformational change of the 30-residue stretch around Ser-23 when mutated to the residues carrying a net negative charge or being phosphorylated. The structural rearrangements occur within the N-terminal helix-loop-helix motif with a set of charged residues. This motif has structural homology with one in the Ca2+-ATPase and may form a function-related structural site in the P-type ATPases. Comparative molecular modeling indicates a lengthening of the interhelical loop and an order-to-disorder transition by disrupting a helix at position 23 because of posphorylation. [ABSTRACT FROM AUTHOR] |
|
Copyright of Cell Biochemistry & Biophysics is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
قاعدة البيانات: |
Complementary Index |