Interaction of V-Myb oncoprotein with spread chromatin of avian haematopoietic cells.

摘要

Interactions of v-Myb oncoprotein with spread chromatin of avian LSCC-BM2 cells expressing v-myb oncogene were studied by means of immunoelectron microscopy. The application of this technique using anti-Myb polyclonal antibody combined with the Miller type spreading for visualisation of chromatin revealed the presence of Myb protein on stretched chromatin fibres. Intense labelling was apparent on the chromatin dispersed by hypotonic treatment, where the label was present frequently in clusters, although individual marks along the fibrillar molecules were also found. The combination of hypotonic and detergent treatment resulted in better dispersal of chromatin, more frequent detection of active transcription units, but also in removal of some proteins from chromatin fibres. The labelling of chromatin with anti-Myb antibody was substantially reduced in this case and was dependent on detergent concentration used. The marker was found less frequently on chromatin fibres usually present in clusters on remaining protein structures. Our findings confirmed direct interaction of v-Myb protein with chromatin structure. This interaction is apparently affected by detergent treatment.