Introduction |
In diploid mammalian
cells, some 6x109 base pairs of DNA
fold as a nucleo-protein complex
(i.e. chromatin) into higher-order arrays so as to fit in a nucleus
measuring
only 10 µm. The nucleus also contains machineries for
transcription of genes
and processing of RNA products, and for precise DNA replication, repair
and
recombination. Nuclear interior is therefore functionally highly
compartmentalized, and the recent evidence points strongly to
structure-related
regulation of nuclear functions – however, the mechanisms forming the
3D-structure of the nucleus are still mostly obscure. We therefore
employ a
multi-disciplinary approach in order to study nuclear functions in
relation to
the higher-order nuclear structures, e.g. nuclear bodies, the
nucleolus, and
the nucleoskeleton. Our research concentrates on:
|
Some of our recent results |
Transport of nuclear myosin I to the nucleus is mediated by NM1 nuclear
localizing signal (NLS) - it is inhibited
by calmodulin overexpression. This suggests that NM1 transport to the
nucleus might be
regulated by calcium levels. |
|
Various
actin-binding proteins were identified in nuclear extracts of Hela
cells. Lamin and tubulin antibodies were used for control of purity of
nuclear (nu) and cytoplasmic (cy) fractions. This information forms a
basis for studying new components of nuclear structures. |
|
Vinculin
is an actin-binding protein which is considered to be exclusively
cytoplasmic. We demonstrate for the first time nuclear localization of
vinculin in intact cells (A). The intensity of the signal becomes
stronger when uncovering the epitopes by the removal of chromatin (B).
Green: antivinculin
antibody; blue: DNA |