Microtubule Integrity Regulates Src-like and Extracellular Signal-regulated Kinase Activities in Human Pro-monocytic Cells

Abstract

(1993) J. Biol. Chem. 268, 13675-13681). Here, we provide evidence that disruption of the microtubule structure rapidly triggers extracellular signal-regulated kinase (ERK) activation, whereas it was without effect on SAPK2 activity, which is commonly acknowledged to control pro-inflammatory cytokine production. This process involves the activation of the entire cascade including Ras, Raf-1, MEK1/2, ERK1, and ERK2. Activation of ERKs is followed by their nuclear translocation. Although other SAPK congeners might be activated upon microtubule depolymerization, the activation of ERK1 and ERK2 is mandatory for IL-1 production as shown by the blocking effect of PD 98059, a specific MEK1/2 inhibitor. Additionally, we provide evidence that microtubule disruption also induces the activation of c-Src and Hck activities. The importance of Src kinases in the mediation of the colchicine effect is underscored by the fact that CP 118556, a specific inhibitor of Src-like kinase, abrogates both the colchicine-induced ERK activation and IL-1 production. This is the first evidence that ERK activation is an absolute prerequisite for induction of this cytokine. Altogether, our data lend support to a model where the status of microtubule integrity controls the level of Src activities that subsequently activate the ERK kinase cascade, thus leading to IL-1 production.

Microtubule-interfering Agents Stimulate the Transcription of Cyclooxygenase-2

“…Although MIAs have been reported to activate gene expression via the Ras pathway (29), to the best of our knowledge this is the first time that the protein kinase C pathway has been implicated. MIAs activate Raf-1 (27), a downstream target of protein kinase C. The induction of COX-2 promoter activity by microtubule-or actin-interfering agents was inhibited by kinase-deficient Raf-1. This is consistent with prior evidence that COX-2 is a Raf-1-dependent gene (48).…”

“…Previously, MIAs were found to induce p38, JNK, and ERK MAPK activities (27)(28)(29)31). The expression of COX-2 can be affected by changes in MAPK activity (48 -52) sary for induction of COX-2.…”

Myc-interacting protein 1 target gene profile: A link to microtubules, extracellular signal-regulated kinase, and cell growth

“…This pathway was of particular interest because of reports showing activation of ERK after disruption of microtubules by using colchicine (7). Activation of Ras leading to activation of ERK also correlates with a decreased stability of microtubules (8).…”

Protein Kinase Activation by Warm And Cold Hypoxia- Reoxygenation in Primary-Cultured Rat Hepatocytes–JNK1/SAPK1 Involvement in Apoptosis

“…The lysates (1 mg) were precleared with rabbit nonimmune serum prebound to protein A-Sepharose (Pharmacia-LKB Biotechnologies, Uppsala, Sweden), and SAP-related kinases were immunoprecipitated from precleared lysates by incubation at 4°C for 16 hours with anti-JNK 1 antisera (Santa Cruz Biotechnology) bound to protein A-sepharose. 39 Immunopellets were washed twice with lysis buffer, twice with MAP kinase buffer (30 mmol/L NaCl, 0.1 % Nonidet P-40, 10 % glycerol, 200 mol/L Na 3 VO 4 , 30 mmol/L Hepes at pH 7.5), and resuspended in 50 L of MAP kinase buffer containing 30 mmol/L Mg-acetate in the presence of 0.5 mg/mL of GST-ATF2, which were used as exogenous substrates for JNK 1 . The kinase assay was initiated by addition of 25 mol/L ATP and 20…”