1997 Fiscal Year Final Research Report Summary
Functional Analysis of Proteins in a Nuclear Matrix Structure
| Project/Area Number |
07680678
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional biochemistry
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| Research Institution | TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY |
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Principal Investigator |
SUGANO Nobuhiko Toyama Med & Pharma Univ, Faculty of Pharmaceutical Science, Professer, 薬学部, 教授 (40019112)
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| Co-Investigator(Kenkyū-buntansha) |
HIBINO Yasuhide Toyama Med & Pharma Univ, Molecular Genetics Research Center, Assistant Professe, 遺伝子実験施設, 助手 (10189805)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Highly Repetitive DNA / Nuclear Matrix / DNA-Binding Protein / Phosphorylation / Matrin 3 |
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| Research Abstract |
Eukaryotic chromosomes are thought to be separated into topologically independent loop domains by periodic attachment onto an intranuclear frame known as the nuclear matrix or nuclear. Specific DNA sequences that bind to the nuclear matrix are called matrix attachment regions (MARs) and these sequences have been postulated to form the base of chromosomal loops. MARs may be important to organize chromosomes and involved in several functions containing transcription and replication. In order to understand the function and structure of the nucleus, we investigated the MARs and MAR-binding proteins from rat-liver nuclei. A highly repetitive DNA has been shown to be one of the components of MARs. Moreover, the DNA fragments had selective affinities for the nuclear scaffold protein, P123 and P130 and AT-rich regions in a component caused bending of the helix axis to be recognized by these proteins. In addition, the binding ability of these proteins for the DNA depended on the phosphorylation of their hydroxyl amino acid residues, especially tyrosine residues. The cDNA of P130 has been cloned and sequenced to contain a large number of amino acid with free hydroxyl groups. This sequence was similar to that of matrin 3 which is rich in nuclear matrix fraction. Matrin 3 had two homologous motifs with the characteristics of a Cys_2-His_2 zinc finger-like motif and two RNA binding motifs. Now, we are planning to investigate the detail function ofthese domains by making mutated proteins. On the other hand, it has been found that the nuclear scaffold fraction from rat-ascites hepatoma cells does not contain these proteins, but does have a repetitive bent DNA-binding protein that has a molecular weight of about 230 kDa. This implies that there is some difference in the structure of nuclear DNA attachment region between rat liver and the hepatoma.
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