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Sequence of LTR of mouse mammary tumor virus and its regulatory factors

小鼠乳腺癌病毒LTR序列及其调控因子

基本信息

批准号：
03670259
负责人：
KOIZUMI Akio
金额：
$ 1.34万
依托单位：
Akita University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03670259/
关键词：
Mouse mammmary SHN mouse Long Terminal Repeat Open Reading Frame Torpor Prolactin Ca^<++>-ATPase マウス乳癌ウィルスオープリリーディングフレーム Torpor Ca^<++>ATPase 乳癌ウイルス PCR 低体温エネルギー制限皮フエネルギ-制限

项目摘要

In the present project, the following findings were made.1) The long terminal repeat (LTR) of endogenous mouse mammary tumor virus (MMTV) in the SHN mouse strain, known to have a high incidence of mammary tumors, was cloned and its sequence was elucidated. In the open reading frame between 280 and 380 codons, many base changes were found when compared with reported murine MMTV sequences. In contrast, the sequence of regulatory area of the present LTR was well preserved.2) The MMTV DNA was found to exist as extrachromosomal DNA fragments in the skin and was proven that it is an entire whole MMTV genome. Its role in the MMTV replicating processes, however, remains unknown.3) It has been known that energy restriction (ER) suppresses gene expression of MMTV, although its mechanisms still remains unknown. We found that ER induced torpor and it, in turn, suppressed cellular proliferation in various organs. Suppression, however, was alleviated by increases in energy consumption or in housing temperatures.4) We found that ER decreased the total amount of RNA specifically as well as numbers of cells. PRL mRNA was, however, decreased by ER to much greater extent than that in actin mRNA, suggesting that PRL mRNA decreased more profoundly than other genes.5) Activities of microsomal Aa^<++>-ATPase was found to be decreased after ER.Their activities were found to be decreased at euthermic body temperatures in brain, liver, and salivary glands, and in these and kidney at heterothermic body temperatures.

本课题主要研究结果如下：1）克隆了SHN小鼠内源性小鼠乳腺肿瘤病毒（MMTV）的长末端重复序列（LTR），并对其序列进行了分析。在开放阅读框架280和380密码子之间，发现许多碱基的变化时，与报告的小鼠MMTV序列相比。2）MMTV DNA在皮肤中以染色体外DNA片段的形式存在，证明它是一个完整的MMTV基因组。3）能量限制（energy restriction，ER）抑制MMTV的基因表达，但其作用机制尚不清楚。我们发现，ER诱导的麻木，它反过来，抑制细胞增殖，在各种器官。然而，通过增加能量消耗或住房温度来减轻抑制。4）我们发现ER特异性地减少RNA总量以及细胞数量。5）雌激素受体作用后，大鼠脑、肝和唾液腺中的Aa^++-ATP酶活性降低，在体温正常时降低，在体温异常时降低。