Cyclin-dependent kinase activating kinase/Cdk7 co-localizes with PKC-iota in human glioma cells

Tissue Cell. 2005 Feb;37(1):53-8. doi: 10.1016/j.tice.2004.10.004. Epub 2005 Jan 25.


Cyclin-dependent kinase activating kinase (CAK) is a trimeric complex composed of cdk7, cyclin H and MAT1. CAK/cdk7 functions as a master cell cycle regulator by phosphorylating cyclin-dependent kinases for cell cycle progression. We have previously reported that protein kinase C-iota (PKC-iota) associates with CAK/cdk7. In this investigation, immunofluorescence confocal microscopy was used to provide further evidence for the co-localization of PKC-iota with CAK/cdk7. PKC-iota was labeled with Alexa Fluor 488 (green fluorescent dye) and CAK/cdk7 was labeled with Alexa Fluor 555 (red fluorescent dye). The fusion of the red and green fluorescent colors produced a yellow color, which was used to quantify co-localization of PKC-iota and CAK/cdk7. Confocal microscopy revealed the co-localization of PKC-iota with CAK/cdk7 in both the cytoplasm and nucleus of U-373 MG cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cell Line, Tumor
  • Cell Nucleus / enzymology*
  • Cyclin-Dependent Kinases / metabolism*
  • Cytoplasm / enzymology*
  • Fluorescent Antibody Technique
  • Glioma / enzymology*
  • Humans
  • Isoenzymes / metabolism*
  • Microscopy, Confocal
  • Protein Kinase C / metabolism*
  • Signal Transduction


  • Isoenzymes
  • Protein Kinase C
  • protein kinase C lambda
  • Cyclin-Dependent Kinases
  • cyclin-dependent kinase-activating kinase