ABSTRACT
Protein kinase CK2 is a highly conserved serine/threonine kinase that is ubiquitously expressed in eukaryotic cells. CK2 is a constitutively active tetrameric enzyme composed of two catalytic alpha and/or alpha'-subunits and two regulatory beta-subunits. There is increasing evidence that the individual subunits may have independent functions and that they are asymmetrically distributed inside the cell. To gain a better understanding of the functions of the individual subunits, we employed a yeast-two-hybrid screen with CK2alpha and CK2alpha'. We identified the motor neuron protein KIF5C as a new binding partner for CK2. The interaction found in the yeast-two-hybrid screen was confirmed by co-sedimentation analysis on a sucrose density gradient and by co-immunoprecipitation analysis. Pull-down experiments and surface plasmon resonance spectrometry revealed a direct binding of KIF5C to CK2alpha'. Co-localization studies with neuroblastoma cells, bone marrow and with primary neurons confirmed the biochemical analysis that KIF5C preferentially bound to CK2alpha'.
Subject(s)
Casein Kinase II/metabolism , Kinesins/metabolism , Protein Subunits/metabolism , Animals , Casein Kinase II/genetics , Cell Line , Humans , Kinesins/genetics , Protein Binding , Protein Interaction Mapping , Protein Isoforms/genetics , Protein Isoforms/metabolism , Protein Subunits/genetics , Surface Plasmon Resonance , Two-Hybrid System TechniquesABSTRACT
The development of hormone-refractory prostate cancer cells is one of the major causes for the progression and high mortality rates in advanced prostate cancer (PCA). While the loss of the androgen receptor (AR) is the predominant mechanism for development of a hormone-insensitive disease in vitro, the first in vivo studies showed that the AR is still expressed or is even overexpressed in hormone-refractory PCA. In view of the increasing cases of PCA in the industrialized Western countries, a series of cell and molecular biological studies has led to the identification of various new factors and mechanisms that play a role during the development of hormone-refractory tumors. These findings should lead to the development of new therapeutic strategies.
Subject(s)
Neoplasms, Hormone-Dependent/genetics , Neoplasms, Hormone-Dependent/therapy , Prostatic Neoplasms/genetics , Prostatic Neoplasms/therapy , Receptors, Androgen/genetics , Androgen Antagonists/therapeutic use , Animals , Cell Line, Tumor , DNA Mutational Analysis , Gene Expression Regulation/physiology , Humans , Male , Polymorphism, Genetic/genetics , Prognosis , Rats , Receptors, Androgen/drug effects , Signal Transduction/geneticsABSTRACT
To determine the effects of nicotine alkaloids on the microcirculation of a variety of tissues, we infused equimolar concentrations (10(-4)-10(-1) M) of 1-nicotine (N), nor-nicotine (NN), dihydro-metanicotine (DHN) in the skeletal muscle, in a skin flap chamber, and in a saline-perfused mesentery preparation of the rat (WistHan). The qualitative and quantitative responses to these equimolar concentrations were measured by modern microcirculatory techniques. Our data showed that 1-nicotine and its alkaloids differ significantly in dose-dependency, maximal vasoactivity, tissue specificity, and microvascular localization. In conclusion, the small differences in the chemical structure of the pyridine ring which distinguishes the alkaloids cause significantly different microvascular effects.
