Predicted methyltransferase that is essential for complex 1 assembly or maintenance and may methylate NDUFB3, complex subunit. C20orf7is peripherally associated with the matrix face of the mitochondrial inner membrane [40]. CaM KMTsh-GFP fusion protein was found to localize to the perinuclear structure resembling that of the Golgi complex in COS-7 and HeLa cells. However, the precise function of this variant remains obscure. The 4th exon specific to this variant is not evolutionary conserved.Figure 5. CaM KMT binds to the middle domain of Hsp90. (A) Schematic representation of the structural domains of human Hsp90 used in these experiments (numbers refer to the sequence of human Hsp90a). (B) Binding of CaM KMT and the middle domain of the Hsp90. GST fused Hsp90 fragments (10 mg protein) used in the pull-down experiments: GST- Hsp90N – N-terminal (9?36aa), GST- Hsp90M – middle domain (273?17aa), GST- Hsp90C- C-terminal (629?32aa), were expressed in E.Coli, purified and immobilized to glutathione agarose beads. After overnight incubation with Myc-CaM KMT transfected HEK293 cells’ lysates, the beads were washed and the bound proteins were subjected to SDS-PAGE. The membrane was stained with ponceau red before immunoblotting to demonstrate similar quantities of GST-Hsp90. Immunoblotting with anti-Myc Title Loaded From File antibody revealed that CaM KMT binds only the middle domain. Representative results from six independent experiments are shown. doi:10.1371/journal.pone.0052425.gCharacterization of CaM KMTFigure 6. Geldanamycin induces degradation of the CaM KMT. HeLa cells transfected with Myc-CaM KMT (A) and with FLAG-CaM KMT (B) cells were treated with increasing concentrations of GA for 24 h, followed by immunoblotting with monoclonal antibodies anti-Myc (A) and antiFLAG (B) to examine protein levels of CaM KMT. Western blot with anti-GAPDH antibody was used as proteins’ loading control. The results shown in (A) are representative of four independent experiments. The results shown in (B) are representative of two independent experiments. doi:10.1371/journal.pone.0052425.gSubsequent to the anti-CaM KMT polyclonal antibodies generation, the CaM KMT expression was confirmed in various mouse tissues: spleen, brain, kidney, liver, heart and muscle. These results 24195657 support the suggestion that CaM KMT is a ubiquitously expressed protein, and highly expressed in the tissues affected in 2p21 deletion syndrome. In this work we have shown that CaM KMT interacts with the Hsp90 protein. Hsp90 is a molecular chaperone and the most abundant heat shock protein under normal conditions. It exhibits ATPase Sense 59TGTGGGAATCCGACGAATG-39 and antisense 59- GTCATATGGTGGAGCTGTGGG-39 for N-Cadherin; sense 59CGGGAATGCAGTTGAGGATC-39 and activity which is essential for its chaperone function. Hsp90 binds to an array of client proteins that require its chaperon function for their folding, stabilization, ligand binding and activation. In addition, Hsp90 interacts with various types of cochaperones, which regulate the ATPase activity of Hsp90, mediate the folding and activation of the client proteins, and direct Hsp90 to interact with specific client proteins [7]. Our mass spectrometry results have shown that both isoforms, Hsp90a and Hsp90b, interact with CaM KMT. We mapped the interaction of CaM KMT with Hsp90 to the middle domain of Hsp90, showing that it is a direct binding, by performing pull-down experiments with Hsp90 purified fragments. The middle domain is known to act as a discriminator between different types of Hsp90 interacting proteins, mostly the client proteins [21]. To verify whether CaM KMT i.Predicted methyltransferase that is essential for complex 1 assembly or maintenance and may methylate NDUFB3, complex subunit. C20orf7is peripherally associated with the matrix face of the mitochondrial inner membrane [40]. CaM KMTsh-GFP fusion protein was found to localize to the perinuclear structure resembling that of the Golgi complex in COS-7 and HeLa cells. However, the precise function of this variant remains obscure. The 4th exon specific to this variant is not evolutionary conserved.Figure 5. CaM KMT binds to the middle domain of Hsp90. (A) Schematic representation of the structural domains of human Hsp90 used in these experiments (numbers refer to the sequence of human Hsp90a). (B) Binding of CaM KMT and the middle domain of the Hsp90. GST fused Hsp90 fragments (10 mg protein) used in the pull-down experiments: GST- Hsp90N – N-terminal (9?36aa), GST- Hsp90M – middle domain (273?17aa), GST- Hsp90C- C-terminal (629?32aa), were expressed in E.Coli, purified and immobilized to glutathione agarose beads. After overnight incubation with Myc-CaM KMT transfected HEK293 cells’ lysates, the beads were washed and the bound proteins were subjected to SDS-PAGE. The membrane was stained with ponceau red before immunoblotting to demonstrate similar quantities of GST-Hsp90. Immunoblotting with anti-Myc antibody revealed that CaM KMT binds only the middle domain. Representative results from six independent experiments are shown. doi:10.1371/journal.pone.0052425.gCharacterization of CaM KMTFigure 6. Geldanamycin induces degradation of the CaM KMT. HeLa cells transfected with Myc-CaM KMT (A) and with FLAG-CaM KMT (B) cells were treated with increasing concentrations of GA for 24 h, followed by immunoblotting with monoclonal antibodies anti-Myc (A) and antiFLAG (B) to examine protein levels of CaM KMT. Western blot with anti-GAPDH antibody was used as proteins’ loading control. The results shown in (A) are representative of four independent experiments. The results shown in (B) are representative of two independent experiments. doi:10.1371/journal.pone.0052425.gSubsequent to the anti-CaM KMT polyclonal antibodies generation, the CaM KMT expression was confirmed in various mouse tissues: spleen, brain, kidney, liver, heart and muscle. These results 24195657 support the suggestion that CaM KMT is a ubiquitously expressed protein, and highly expressed in the tissues affected in 2p21 deletion syndrome. In this work we have shown that CaM KMT interacts with the Hsp90 protein. Hsp90 is a molecular chaperone and the most abundant heat shock protein under normal conditions. It exhibits ATPase activity which is essential for its chaperone function. Hsp90 binds to an array of client proteins that require its chaperon function for their folding, stabilization, ligand binding and activation. In addition, Hsp90 interacts with various types of cochaperones, which regulate the ATPase activity of Hsp90, mediate the folding and activation of the client proteins, and direct Hsp90 to interact with specific client proteins [7]. Our mass spectrometry results have shown that both isoforms, Hsp90a and Hsp90b, interact with CaM KMT. We mapped the interaction of CaM KMT with Hsp90 to the middle domain of Hsp90, showing that it is a direct binding, by performing pull-down experiments with Hsp90 purified fragments. The middle domain is known to act as a discriminator between different types of Hsp90 interacting proteins, mostly the client proteins [21]. To verify whether CaM KMT i.
