テロメアの長さと機能の調節は,分裂酵母におけるMybドメインタンパク質によって行われます

J P Cooper¹, E R Nimmo, R C Allshire

¹Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309, USA.

Nature

|February 20, 1997

まとめ

Taz1pは,新しい分裂酵母テロメアタンパク質で,テロメアの長さと遺伝子発現を調節するために重要です. 欠乏すると,テロメアが劇的に延長され,メオシスの障害が生じます.

科学分野:

分子生物学は分子生物学である.
遺伝学遺伝学とは
細胞生物学細胞生物学

背景:

テロメアは,複製とゲノム安定のために不可欠な真核染色体の保護キャップです.
テロメア長さの調節は,腫瘍発生研究において極めて重要です.
既知のテロメア結合タンパク質には,芽生えた酵母におけるRap1pとヒトにおけるhTRFが含まれるが,hTRFの機能は不明である.

研究の目的:

分裂酵母における新しいテロメア関連タンパク質を特定し,特徴づけること.
テロメア長さの調節,遺伝子発現,そして半分裂におけるTaz1pの機能を調査する.

主な方法:

テロメア関連タンパク質を特定するために,分裂酵母 (Schizosaccharomyces pombe) の遺伝子スクリーニング.
遺伝子の破壊と,特定された taz1+ 遺伝子の削除.
テロメア長さ,テロメア付近の遺伝子発現,およびメオティック進行の分析.

主要な成果:

Taz1pの識別,ヒトのhTRFに同質な分裂酵母タンパク質で,Myb DNA結合ドメインを共有しています.
taz1+遺伝子の破壊により,テロメアの長さが大幅に増加しました.
Taz1pは,テロメア付近の遺伝子の転写を抑制し,正常な介質過程のために不可欠です.

結論:

Taz1pは,分裂酵母におけるテロメアの長さのホメオスタシスを維持する上で重要な役割を果たします.
Taz1pは,テロメア長さの負の調節剤として機能し,テロメラーゼの活性やテロメラーゼに依存しない延長経路を阻害することによって,テロメラーゼの長さを抑制する可能性があります.
Taz1pはまた,テロメア近接領域の遺伝子発現の調節に関与しており,適切なメオティック機能に不可欠です.

さらに関連する動画

12:04

Examination of Mitotic and Meiotic Fission Yeast Nuclear Dynamics by Fluorescence Live-cell Microscopy

Published on: June 24, 2019

11:21

Analyzing Telomeric Protein-DNA Interactions Using Single-Molecule Magnetic Tweezers

Published on: August 30, 2024

関連する概念動画

02:31

Replication in Eukaryotes

Overview

02:41

Telomeres and Telomerase

In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.

02:15

Replicative Cell Senescence

Replicative cell senescence is a property of cells that allows them to divide a finite number of times throughout the organism's lifespan while preventing excessive proliferation. Replicative senescence is associated with the gradual loss of the telomere — short, repetitive DNA sequences found at the end of the chromosomes. Telomeres are bound by a group of proteins to form a protective cap on the ends of chromosomes. Embryonic stem cells express telomerase — an enzyme that adds the telomeric...

02:36

Cells Coordinate Growth and Proliferation

Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...

01:29

Replication in Eukaryotes

In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...