Integrin-Linked Kinase Is a Functional Mn2+-Dependent Protein Kinase that Regulates Glycogen Synthase Kinase-3β (GSK-3β) Phosphorylation
Wölfl, Stefan, Maydan, Mykola, McDonald, Paul C., Sanghera, Jasbinder, Yan, Jun, Rallis, C., Pinchin, Sheena, Hannigan, Gregory E., Foster, Leonard J., Ish-Horowicz, David, Walsh, Michael P. and Dedhar, Shoukat 2010. Integrin-Linked Kinase Is a Functional Mn2+-Dependent Protein Kinase that Regulates Glycogen Synthase Kinase-3β (GSK-3β) Phosphorylation. PLOS ONE. 5 (8), p. e12356. https://doi.org/10.1371/journal.pone.0012356
|Authors||Wölfl, Stefan, Maydan, Mykola, McDonald, Paul C., Sanghera, Jasbinder, Yan, Jun, Rallis, C., Pinchin, Sheena, Hannigan, Gregory E., Foster, Leonard J., Ish-Horowicz, David, Walsh, Michael P. and Dedhar, Shoukat|
Integrin-linked kinase (ILK) is a highly evolutionarily conserved, multi-domain signaling protein that localizes to focal adhesions, myofilaments and centrosomes where it forms distinct multi-protein complexes to regulate cell adhesion, cell contraction, actin cytoskeletal organization and mitotic spindle assembly. Numerous studies have demonstrated that ILK can regulate the phosphorylation of various protein and peptide substrates in vitro, as well as the phosphorylation of potential substrates and various signaling pathways in cultured cell systems. Nevertheless, the ability of ILK to function as a protein kinase has been questioned because of its atypical kinase domain.
Here, we have expressed full-length recombinant ILK, purified it to >94% homogeneity, and characterized its kinase activity. Recombinant ILK readily phosphorylates glycogen synthase kinase-3 (GSK-3) peptide and the 20-kDa regulatory light chains of myosin (LC20). Phosphorylation kinetics are similar to those of other active kinases, and mutation of the ATP-binding lysine (K220 within subdomain 2) causes marked reduction in enzymatic activity. We show that ILK is a Mn-dependent kinase (the Km for MnATP is ∼150-fold less than that for MgATP).
Taken together, our data demonstrate that ILK is a bona fide protein kinase with enzyme kinetic properties similar to other active protein kinases.
|Journal citation||5 (8), p. e12356|
|Publisher||Public Library of Science|
|Digital Object Identifier (DOI)||https://doi.org/10.1371/journal.pone.0012356|
|Web address (URL)||https://doi.org/10.1371/journal.pone.0012356|
|23 Aug 2010|
|Publication process dates|
|Deposited||13 Feb 2018|
|Accepted||29 Jul 2010|
|Accepted||29 Jul 2010|
|Funder||Canadian Cancer Society Research Institute|
|Cancer Research UK|
|Canadian Institutes of Health Research|
|Copyright information||© 2010 The authors|
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