人間のミトスチェックポイント遺伝子の特定: hsMAD2
1Cell Biology and Genetics Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
Science (New York, N.Y.)
|October 11, 1996
まとめ
ヒトのMAD2タンパク質は,ミトスのチェックポイントに不可欠であり,適切な細胞分裂を保証します. 乳がん細胞におけるMAD2の減少は,このチェックポイントを損なっており,がん薬に対する感受性を説明する可能性がある.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- スピンドル・アセンブリ・チェックポイント (SAC) は,細胞分裂中の正確な染色体分離に不可欠です.
- MAD2は,SACの重要な構成要素であり,スピンドル組成が故障したときにミトの停止を保証します.
研究 の 目的:
- ヒトのMAD2ホモログ (hsMAD2) がミトーシスチェックポイントにおける役割を調査する.
- 人間の細胞におけるhsMAD2の局所と機能を決定する.
- MAD2発現とミトーシス阻害剤に対する腫瘍感受性との潜在的な関連性を調査する.
主な方法:
- 人間のMAD2 (hsMAD2) の分離と特徴づけ.
- hsMAD2の機能を評価するために,HeLa細胞における抗体電解.
- 免疫光顕微鏡でhsMAD2の局所化を決定する.
- T47D乳がん細胞におけるMAD2発現の分析.
主要な成果:
- 人間のMAD2は,スピンドルアセンブリの欠陥に対する反応としてミトの停止に不可欠です.
- hsMAD2は染色体凝縮後にキネトコアに局所化し,メタフェーズによって消失します.
- この局所化は,hsMAD2がスパインドル-キネトコア結合をモニターしていることを示唆している.
- MAD2発現が低下したT47D乳がん細胞は,ノコダゾールで治療したときにミトーシスを止めることができませんでした.
結論:
- hsMAD2はヒトのミトーシスチェックポイントの重要な構成要素です.
- MAD2のダイナミックなキネトコア・ローカライゼーションは,適切なスパインドルの固定を確保する役割を示しています.
- ミトシスチェックポイントの欠陥は,潜在的にMAD2の減少によるもので,タクソールやノコダゾールのようなミトシススパインドル阻害剤に対する腫瘍の感受性に寄与する可能性があります.
関連する概念動画
01:23Negative Regulator Molecules
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
02:36DNA Damage can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
02:15M-Cdk Drives Transition Into Mitosis
Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
02:23Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
02:02Meiosis II
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...