Nucleolus, in which rRNA precursors are synthesized and subunits of ribosomesare assembled, is composed of many copies of rDNA, rRNA and many kinds ofproteins. The processing of rRNA precursors also occurs in nucleolu...Nucleolus, in which rRNA precursors are synthesized and subunits of ribosomesare assembled, is composed of many copies of rDNA, rRNA and many kinds ofproteins. The processing of rRNA precursors also occurs in nucleolus, which is associ-ated with some nonribosomal proteins. In the 1980s, scientists proposed thatnucleolar skeleton or nucleolar matrix which is mainly constructed with proteins展开更多
Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown a...Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown as a fine network under electron microscope with DGD embedding-unembedding technique. Such structures of BHK-21 cell and mouse liver cell are similar to that of HeLa cell. The protein composition of the nucleolar skeleton of HeLa cells was analyzed. The protein composition of such nucleolar residual shows obvious difference from the compositions of nuclear matrix and chromosome scaffold. The major protein composition of the nucleolar skeleton of HeLa cells contains 6-7 polypeptides. Their molecular weights are about 48, 43, 36 and 33 ku. Further studies show that actin and fib-rillarin are two major protein components of nucleolar skeleton of HeLa cells.展开更多
文摘Nucleolus, in which rRNA precursors are synthesized and subunits of ribosomesare assembled, is composed of many copies of rDNA, rRNA and many kinds ofproteins. The processing of rRNA precursors also occurs in nucleolus, which is associ-ated with some nonribosomal proteins. In the 1980s, scientists proposed thatnucleolar skeleton or nucleolar matrix which is mainly constructed with proteins
文摘Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown as a fine network under electron microscope with DGD embedding-unembedding technique. Such structures of BHK-21 cell and mouse liver cell are similar to that of HeLa cell. The protein composition of the nucleolar skeleton of HeLa cells was analyzed. The protein composition of such nucleolar residual shows obvious difference from the compositions of nuclear matrix and chromosome scaffold. The major protein composition of the nucleolar skeleton of HeLa cells contains 6-7 polypeptides. Their molecular weights are about 48, 43, 36 and 33 ku. Further studies show that actin and fib-rillarin are two major protein components of nucleolar skeleton of HeLa cells.
