MRT67307

MRT67307 is a dual inhibitor of the IKKε and TBK-1 with IC50s of 160 and 19 nM, respectively. MRT67307 also inhibits ULK1 and ULK2 with IC50s of 45 and 38 nM, respectively.

Signaling Pathways >> Autophagy >> Autophagy

Signaling Pathways >> NF-κB >> IKK

Signaling Pathways >> Autophagy >> ULK

Research Areas >> Inflammation/Immunology

TBK1:19 nM (IC50, at 0.1 mM ATP)

IKKε:160 nM (IC50, at 0.1 mM ATP)

ULK1:45 nM (IC50)

ULK2:38 nM (IC50)

Autophagy

MRT67307 actually enhances phosphorylation in IKKα−/− MEFs, the IL-1-stimulated phosphorylation of p105 at Ser933 and RelA at both Ser468 and Ser536. MRT67307 also enhances IL-1-stimulated activation of NF-κB-dependent gene transcription in wild-type MEFs. Treatment of macrophages with MRT67307 leads to an increase in the poly(I:C)- and LPS-stimulated phosphorylation of p105 and RelA and enhanced NF-κB transcriptional activity[1]. MRT67307 (10 μM) is sufficient to reduce phospho-ATG13 to control levels, and in line with the in vitro IC50 values, 10-fold less MRT68921 (1 μM) results in a similar reduction. MRT67307 and MRT68921 inhibit ULK and block autophagy in cells[2]. MRT67307 increases IL-10 production and suppresses proinflammatory cytokine production in macrophages. MRT67307 increases CREB-dependent gene transcription by promoting the dephosphorylation of CRTC3. MRT67307 does not inhibit the brain-specific kinases (BRSKs) and only inhibits the maternal embryonic leucine zipper kinase (MELK) and AMPK itself more weakly[3].

Substrates and kinases are diluted in 50 mM Tris/HCl (pH 7.5), 0.1% 2-mercaptoethanol, 0.1 mM EGTA and 10 mM magnesium acetate. Reactions are initiated with [γ-32P]ATP (2500 c.p.m./pmol) to a final concentration of 0.1 mM and terminated after 15 min at 30°C by the addition of SDS and EDTA (pH 7.0) to final concentrations of 1.0% (w/v) and 20 mM respectively. After heating for 5 min at 100°C and separation by SDS/PAGE, the phosphorylated proteins are detected by autoradiography.

Cells are rinsed in ice-cold PBS and extracted in lysis buffer (50 mM Tris·HCl at pH 7.4, 1 mM EDTA, 1 mM EGTA, 50 mM NaF, 5 mM sodium pyrophosphate, 10 mM sodium β-glycerol 1-phosphate, 1 mM DTT, 1 mM sodium orthovanadate, 0.27mol/Lsucrose, 1% (vol/vol) Triton X-100, 1 μg/mL aprotinin, 1 μg/ mL leupeptin, and 1 mM phenylmethylsulphonyl fluoride). Cell extracts are clarified by centrifugation at 14,000 × g for 10 min at 4°C, and protein concentrations are determined by using the Bradford assay. FLAG-CRTC3 is purified on anti-FLAG M2 agarose, whereas endogenous CRTC3 is immunoprecipitated from cell extracts by using anti-CRTC3 raised against the peptide CWKEEKHPGFR (S277D bleed 2) and coupled to Protein GSepharose. To detect proteins in cell lysates, 20 μg of protein extract is separated by SDS/PAGE. After transfer to PVDF membranes, proteins are detected by immunoblotting and visualized by treating the blots with ECL followed by autoradiography. The following antibodies are used for immunoblotting: pSer133 CREB, pSer171 CRTC2, total CRTC2, GAPDH, total STAT3, pTyr705 STAT3, FLAG (M2 clone), CRTC3, HA (3F10), and 14-3-3; and antibodies against pSer329 (S256D bleed 2) and pSer370 (S253D bleed 2) of CRTC3 are raised against the phosphopeptides GLQSSRpSNPSIQ and RLFSLpSNPSLST.

[1]. Clark K, et al. Novel cross-talk within the IKK family controls innate immunity. Biochem J. 2011 Feb 15;434(1):93-104.

[2]. Petherick KJ, et al. Pharmacological inhibition of ULK1 kinase blocks mammalian target of rapamycin (mTOR)-dependent autophagy. J Biol Chem. 2015 May 1;290(18):11376-83.

[3]. Clark K, et al. Phosphorylation of CRTC3 by the salt-inducible kinases controls the interconversion of classically activated and regulatory macrophages. Proc Natl Acad Sci U S A. 2012 Oct 16;109(42):16986-91.

Resveratrol | SBI-0206965 | BMS-345541 | MRT-68921 hydrochloride | MLN120B | ACHP (Hydrochloride) | TPCA-1 | IKK-16 | IMD 0354 | LY2409881 | SC-514 | BI 605906 | Bay 65-1942 (hydrochloride) | TBK1/IKKε-IN-2