TY - JOUR
T1 - The KLDpT activation loop motif is critical for MARK kinase activity
AU - Sonntag, Tim
AU - Moresco, James J.
AU - Yates, John R.
AU - Montminy, Marc
N1 - Funding Information:
This work was supported by the NIH grant R01 DK083834, the Leona M. and Harry B. Helmsley Charitable Trust (https://helmsleytrust. org/), the Clayton Foundation for Medical Research, the J.W. Kieckhefer Foundation, NIH-NCI CCSG: P30 014195, NINDS Neuroscience Core Grant: NS072031, and the Waitt Foundation. JJM and JRY were supported by the National Institute of General Medical Sciences (8 P41 GM103533). None of the funders had a role in study design, data collection and analysis, decision to publish, or preparation of this manuscript. We thank Dr. Olga Göransson (Lund University) for the phospho-specific SIK2 S358 antibody [34].
Publisher Copyright:
© 2019 Sonntag et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - MAP/microtubule-affinity regulating kinases (MARK1-4) are members of the AMPK family of Ser/Thr-specific kinases, which phosphorylate substrates at consensus LXRXXSXXXL motifs. Within microtubule-associated proteins, MARKs also mediate phosphorylation of variant KXGS or ζXKXGSXXNΨ motifs, interfering with the ability of tau and MAP2/4 to bind to microtubules. Here we show that, although MARKs and the closely related salt-inducible kinases (SIKs) phosphorylate substrates with consensus AMPK motifs comparably, MARKs are more potent in recognizing variant ζXKXGSXXNΨ motifs on cellular tau. In studies to identify regions of MARKs that confer catalytic activity towards variant sites, we found that the C-terminal kinase associated-1 (KA1) domain in MARK1-3 mediates binding to microtubule-associated proteins CLASP1/2; but this interaction is dispensable for ζXKXGSXXNΨ phosphorylation. Mutational analysis of MARK2 revealed that the N-terminal kinase domain of MARK2 is sufficient for phosphorylation of both consensus and variant ζXKXGSXXNΨ sites. Within this domain, the KLDpT activation loop motif promotes MARK2 activity both intracellularly and in vitro, but has no effect on SIK2 activity. As KLDpT is conserved in all vertebrates MARKs, we conclude that this sequence is crucial for MARK-dependent regulation of cellular polarity.
AB - MAP/microtubule-affinity regulating kinases (MARK1-4) are members of the AMPK family of Ser/Thr-specific kinases, which phosphorylate substrates at consensus LXRXXSXXXL motifs. Within microtubule-associated proteins, MARKs also mediate phosphorylation of variant KXGS or ζXKXGSXXNΨ motifs, interfering with the ability of tau and MAP2/4 to bind to microtubules. Here we show that, although MARKs and the closely related salt-inducible kinases (SIKs) phosphorylate substrates with consensus AMPK motifs comparably, MARKs are more potent in recognizing variant ζXKXGSXXNΨ motifs on cellular tau. In studies to identify regions of MARKs that confer catalytic activity towards variant sites, we found that the C-terminal kinase associated-1 (KA1) domain in MARK1-3 mediates binding to microtubule-associated proteins CLASP1/2; but this interaction is dispensable for ζXKXGSXXNΨ phosphorylation. Mutational analysis of MARK2 revealed that the N-terminal kinase domain of MARK2 is sufficient for phosphorylation of both consensus and variant ζXKXGSXXNΨ sites. Within this domain, the KLDpT activation loop motif promotes MARK2 activity both intracellularly and in vitro, but has no effect on SIK2 activity. As KLDpT is conserved in all vertebrates MARKs, we conclude that this sequence is crucial for MARK-dependent regulation of cellular polarity.
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U2 - 10.1371/journal.pone.0225727
DO - 10.1371/journal.pone.0225727
M3 - Article
C2 - 31794565
AN - SCOPUS:85076163267
SN - 1932-6203
VL - 14
JO - PloS one
JF - PloS one
IS - 12
M1 - e0225727
ER -