Immobility, inheritance and plasticity of shape of the yeast nucleus
1 Cell Biology Program, Case Western Reserve University, 10700 Euclid Avenue, Cleveland, OH, 44106 USA
2 Department of Pathology Case Western Reserve University, 10700 Euclid Avenue, Cleveland, OH, 44106, USA
3 Department of Molecular Biology and Microbiology, Case Western Reserve University, 10700 Euclid Avenue, Cleveland, OH, 44106, USA
BMC Cell Biology 2007, 8:47 doi:10.1186/1471-2121-8-47Published: 9 November 2007
Since S. cerevisiae undergoes closed mitosis, the nuclear envelope of the daughter nucleus is continuous with that of the maternal nucleus at anaphase. Nevertheless, several constitutents of the maternal nucleus are not present in the daughter nucleus. The present study aims to identify proteins which impact the shape of the yeast nucleus and to learn whether modifications of shape are passed on to the next mitotic generation. The Esc1p protein of S. cerevisiae localizes to the periphery of the nucleoplasm, can anchor chromatin, and has been implicated in targeted silencing both at telomeres and at HMR.
Upon increased Esc1p expression, cell division continues and dramatic elaborations of the nuclear envelope extend into the cytoplasm. These "
Esc1p is the first non-membrane protein of the nuclear periphery which – like proteins of the nuclear lamina of higher eukaryotes – can modify the shape of the yeast nucleus. The elaborations of the nuclear envelope ("escapades") which appear upon induction of excess Esc1p are not inherited during mitotic growth. The lack of inheritance of such components could help sustain cell growth when parental nuclei have acquired potentially deleterious characteristics.