0389005 - ÚMG 2014 JP eng C - Conference Paper (international conference)
Hozák, Pavel
Nanoparticle-Based Immunocytochemistry Reveals Microarchitecture of the Cell Nucleus.
Beyond the Limit of Histochemistry - 14th INTERNATIONAL CONGRESS OF HISTOCHEMISTRY AND CYTOCHEMISTRY. Kyoto: International Federation of Societies for Histochemistry and Cytochemistry, Japan Society of Histochemistry, 2012.
[14th International Congress of Histochemistry and Cytochemistry. Kyoto (JP), 26.08.2012-29.08.2012]
R&D Projects: GA ČR GAP305/11/2232; GA MŠMT LC545; GA MŠMT(CZ) LC06063; GA MPO(CZ) FRTI3588
Institutional research plan: CEZ:AV0Z50520514
Institutional support: RVO:68378050
Keywords : PIP2 * NMI * cell nucleus
Subject RIV: EB - Genetics ; Molecular Biology

I will summarize the current possibilities of TEM visualization of molecules in cells. In order to overcome the current limitations of immunodetection, we prepared a set of novel nanoparticles (NPs) which fulfill several criteria: size in the frame of 5-12 nm, small size distribution, good contrast and stability in the electron microscope, stability of colloidal solution during conjugation, and surface properties allowing for conjugation with antibodies With the use of novel NPs, various combinations with commercial gold NPs can be made to obtain a set for simultaneous labeling. For the first time in ultrastructural histochemistry, up to five molecular targets can be identified simultaneously. These methods allowed us to progress with understanding some novel molecular interactions in the cell nucleus. I will discuss interactions of phosphatidylinositol-4,5-bisphosphate (PIP2) and nuclear myosin I (NMI) which are involved in regulation of gene expression. PIP2 resides in the nucleus in a different form than the classical bilayer membrane, apparently forming specific nuclear protein complexes. Our data suggest that nucleolar PIP2 might serve as a transcription factor for ribosomal genes. We therefore investigated PIP distribution in cell nuclei with a special attention to nucleoli by ultrastructural tomography, and mapped PIP colocalization with various factors involved in RNA pol I transcription. We also showed in living cells that NM1 binds to PIP2 in the cell nucleus, and this was further confirmed by electron microscopy and molecular approaches. The results will be discussed in the frame of the current model of the nucleolus and lipid functions in the cell nucleus.
Permanent Link: http://hdl.handle.net/11104/0228420