Autoregulatory control of microtubule binding in doublecortin-like kinase 1

Abstract

The microtubule-associated protein, doublecortin-like kinase 1 (DCLK1), is highly expressed in a range of cancers and is a prominent therapeutic target for kinase inhibitors. The physiological roles of DCLK1 kinase activity and how it is regulated remain elusive. Here, we analyze the role of mammalian DCLK1 kinase activity in regulating microtubule binding. We find that DCLK1 autophosphorylates a residue within its C-terminal tail to restrict its kinase activity and prevent aberrant hyperphosphorylation within its microtubule-binding domain. Removal of the C-terminal tail or mutation of this residue causes an increase in phosphorylation within the doublecortin domains, which abolishes microtubule binding. Therefore, autophosphorylation at specific sites within DCLK1 have diametric effects on the molecule's association with microtubules. Our results suggest a mechanism by which DCLK1 modulates its kinase activity to tune its microtubule-binding affinity. These results provide molecular insights for future therapeutic efforts related to DCLK1's role in cancer development and progression.

Doublecortin-Like Kinase 1 Facilitates Dendritic Spine Growth of Pyramidal Neurons in Mouse Prefrontal Cortex

“…After spines are produced, there may be a temporally regulated shift of NrCAM binding from DCLK1 to Ankyrin, possibly regulated by tyrosine dephosphorylation of NrCAM at the FIGQY motif. With respect to additional modes of DCLK1 regulation, recent research has shown that DCLK1 autophosphorylates on its carboxyl terminal tail, which inhibits microtubule binding (Agulto et al, 2021). Future studies with the Nex1Cre-ERT2: DCLK1 flox/flox : RCE mice will be aimed at determining if loss of DCLK1 from pyramidal neurons impairs excitatory transmission or behavior due to reduction of spine density on apical dendrites of cortical pyramidal neurons in the prefrontal cortex.…”

The kinase activity of the cancer stem cell marker DCLK1 drives gastric cancer progression by reprogramming the stromal tumor landscape

“…Moreover, we and others have shown that the DCLK1 kinase domain negatively regulates microtubule polymerization, at least in vitro , and the C-terminal autoinhibitory domain (AID) of DCLK1 competes with ATP for access to the catalytic kinase domain of DCLK1, thus negatively regulating the kinase activity of DCLK1 ( 29, 31, 54 ). Notably, cancer-associated mutations in the AID domain lead to elevated kinase activity and reduced microtubule binding ( 54, 55 ). Both full-length and short isoforms have documented pro-EMT and pro-cancer functions and their kinase activity is blocked by DCLK1-IN-1 ( 30, 56–58 ).…”

Targeting Doublecortin-Like Kinase 1 (DCLK1)-Regulated SARS-CoV-2 Pathogenesis in COVID-19

“…DCLK1 also autophosphorylates its C terminus at T688 residue to block hyperphosphorylation of N-terminal doublecortin domains. Hypophosphorylated and unphosphorylated doublecortin domains bind microtubules with higher affinity ( 49 ). Inhibition of T688 phosphorylation by DCLK1-IN-1 can disrupt DCLK1 interactions with microtubules and inhibition of the movement of viral RNA replication complexes.…”