Nuclear matrix proteome analysis of Drosophila melanogaster.

The nucleus is a highly structured organelle and contains many functional compartments. Although the structural basis for this complex spatial organization of compartments is unknown, a major component of this organization is likely to be the non-chromatin scaffolding called nuclear matrix (NuMat). Experimental evidence over the past decades indicates that most of the nuclear functions are at least transiently associated with the NuMat, although the components of NuMat itself are poorly known. Here, we report NuMat proteome analysis from Drosophila melanogaster embryos and discuss its links with nuclear architecture and functions. In the NuMat proteome, we found structural proteins, chaperones, DNA/RNA-binding proteins, chromatin remodeling and transcription factors. This complexity of NuMat proteome is an indicator of its structural and functional significance. Comparison of the two-dimensional profile of NuMat proteome from different developmental stages of Drosophila embryos showed that less than half of the NuMat proteome is constant, and the rest of the proteins are stage-specific dynamic components. These NuMat dynamics suggest a possible functional link between NuMat and embryonic development. Finally, we also showed that a subset of NuMat proteins remains associated with the mitotic chromosomes, implicating their role in mitosis and possibly the epigenetic cellular memory. NuMat proteome analysis provides tools and opens up ways to understand nuclear organization and function.