Name: how cells control gene expression
Uploaded: 2023-06-23T15:38:45.000Z
Duration: 1 min 23 s
Channel: JoVE

K12 Standards

Georgia Standards of Excellence

9-12

Biology

SB2.a

regulation-of-expression-at-multiple-steps

Regulation of Expression at Multiple Steps

細胞は、転写、mRNAプロセシング、および翻訳中に遺伝子発現を正確に調節します。
転写制御は、DNA上の調節配列に結合して特定の遺伝子の転写を阻害または開始するタンパク質によって媒介されます。
転写によって生成された前駆体mRNAは、5プライムキャップと3プライムポリAテールを付加することで修飾されます。mRNAはスプライシングを受け、非コード領域が除去され、コード領域が結合されて成熟mRNAが生成されます。この段階では、示差スプライシングパターンとRNA結合タンパク質が遺伝子発現を調節します。
RNA結合タンパク質と結合してリボ核タンパク質粒子を形成するmRNAのみが、翻訳のために細胞質に選択的に輸送されます。
翻訳調節は特異的であり得、特定のmRNAサブセットの翻訳の阻害は、タンパク質、マイクロRNA、および短干渉またはsiRNAとの相互作用を通じて制御されます。
対照的に、一般的な翻訳調節は、翻訳機構のタンパク質を活性化または阻害して、すべての転写産物に影響を与えます。

複数のステップでの発現の規制

細胞内の遺伝子発現は、さまざまな段階で調節されています：（i）転写、（ii）RNA処理、（iii）RNAの局在、および（iv）翻訳。転写の調節は、転写因子、活性化因子、または抑制因子などの調節タンパク質によって介在されます-これらは遺伝子の転写を開始または抑制することによって遺伝子発現を制御します。前駆体または前mRNAが生成されると、それは5'キャッピング、スプライシング、および3'ポリAテールの付加などのポスト転写修飾を受け、成熟mRNAを形成します。リボ核タンパク質粒子を形成するRNA結合タンパク質（RBP）とのみ結合する成熟mRNAのみが分解を防ぎ、タンパク質合成のために核外に選択的に輸送されます。RBPと結合しないmRNAは核外に輸送されず、タンパク質に翻訳されません。また、成熟mRNAが相補的なmicroRNAに結合する場合、分解を受けてタンパク質の合成が阻害されます。 しかし、mRNAが翻訳されると、新しく合成されたタンパク質は活性に影響する修飾を受けます。たとえば、メチル基、リン酸またはアセチル基などの機能基が付加されると、タンパク質の活性化または非活性化が起こる場合があります。対照的に、多くのユビキチンタンパク質が基質タンパク質に結合することによって、それらは分解のためにマークされます。したがって、ユビキチン化はタンパク質の安定性と機能活性を調節します。

細胞内での遺伝子発現は、(i)転写、(ii)RNAプロセシング、(iii)RNA局在、(iv)翻訳など、さまざまな段階で制御されています。...

Education

JoVE Core

Anatomy and Physiology

解剖生理学

Unit 1

ユニット1

Essential Cellular Processes

細胞の基本的プロセス

KEY TERMS AND CONCEPTS

主要用語と概念

how cells control gene expression

Cells control gene expression at several stages, from making RNA to building protein. These checkpoints include transcription, RNA processing, RNA localization, and translation. Together, they help decide when a gene is used and whether a protein is made.

Transcription is controlled by regulatory proteins. Transcription factors, activators, and repressors can start or slow the transcription of genes. After transcription, the cell makes a precursor RNA, also called pre-mRNA.

Pre-mRNA must be processed before it can be used. It receives a 5' cap, its introns are removed by splicing, and a 3' poly-A tail is added. These changes produce mature mRNA.

Only some mature mRNAs leave the nucleus. When mRNA binds RNA-binding proteins, or RBPs, it forms a ribonucleoprotein particle that helps protect it from degradation and allows selective transport out of the nucleus for protein synthesis. mRNAs that do not bind RBPs stay in the nucleus and are not translated into protein.

Gene expression can also be turned down after mRNA is made. If a mature mRNA binds a complementary microRNA, the mRNA is degraded and protein synthesis is blocked. After translation, the new protein can still be changed by modification.

Protein modification can change activity and stability. Adding methyl, phosphate, or acetyl groups may activate or inactivate a protein. Adding multiple ubiquitin proteins marks a substrate protein for degradation, which helps control protein stability and function.

How Cells Control Gene Expression

the central dogma

Central Dogma: DNA to Protein

The central dogma explains how genetic information flows in cells from DNA to RNA to protein. It is a core idea in molecular biology and helps show how genes influence cell function. DNA stores the instructions. During transcription, a cell copies a gene into RNA, which is a related nucleic acid. That RNA message can then be used in translation to build a protein. Proteins carry out many jobs in cells and help determine traits. The central dogma links the genetic code in DNA to the molecules...

replication in eukaryotes

Eukaryotic DNA Copying at the Replication Fork

Eukaryotic DNA copying happens at replication forks, where the two DNA strands separate and new strands are built. This process lets a cell make an exact copy of its genetic material before it divides. The transcript explains that eukaryotic replication follows the same basic steps seen in other DNA replication systems, but it takes place in cells with a nucleus. The replication machinery works on each separated strand as a template, so the new DNA matches the original sequence. This topic is...

types of rna

RNA Types in Gene Expression

RNA types play different roles in gene expression. RNA, or ribonucleic acid, helps carry and use genetic information in cells. The main types discussed here are messenger RNA, ribosomal RNA, and transfer RNA. Messenger RNA, or mRNA, carries the genetic code from DNA to the ribosome. The ribosome is the site where proteins are made. Ribosomal RNA, or rRNA, is a key part of the ribosome itself. Transfer RNA, or tRNA, brings the correct amino acids to the ribosome during protein building. These...

transcription

Transcription and RNA Synthesis

Transcription is the process of making RNA from a DNA template. It is a key step in gene expression, because cells use the DNA sequence to build an RNA copy that can carry the message forward. During transcription, RNA polymerase binds to DNA and reads one strand as the template. The enzyme links RNA nucleotides together in the correct order to form a growing RNA molecule. This copying step does not make DNA; it produces RNA. The transcript focuses on the central idea of transcription as DNA...

translation

Translation: mRNA to Protein

Translation is the step in gene expression where ribosomes use messenger RNA, or mRNA, to build a protein. The mRNA sequence carries the instructions copied from DNA. During translation, those instructions are read in order so the cell can make a specific chain of amino acids. This process depends on the ribosome and transfer RNA, or tRNA. The ribosome reads the mRNA, and tRNA brings the matching amino acids. As the chain grows, the amino acids are linked together to form a polypeptide, which...

regulation of expression at multiple steps

Cells control gene expression at several stages, from making RNA to building protein. These checkpoints include transcription, RNA processing, RNA localization, and translation. Together, they help decide when a gene is used and whether a protein is made. Transcription is controlled by regulatory proteins. Transcription factors, activators, and repressors can start or slow the transcription of genes. After transcription, the cell makes a precursor RNA, also called pre-mRNA. Pre-mRNA must be...

what is the cell cycle?

Cell Cycle Stages in Cell Growth

The cell cycle is the process that controls cell growth and division. It explains how one cell makes two new cells. This process helps cells grow and reproduce.

interphase

Interphase and Cell Growth

Interphase is the part of the cell cycle when a cell grows and prepares to divide. It is a major stage of the cell cycle, and it comes before cell division begins. During interphase, the cell carries out its normal functions. It also copies its DNA so each new cell can receive a full set of genetic material. The cell may also build up the materials it needs for division. Interphase is not a single step. It includes phases such as G1, S, and G2, which help the cell grow, copy DNA, and get...

mitosis and cytokinesis

Cell Division: Mitosis and Cytokinesis

Cell division depends on mitosis and cytokinesis. Mitosis is the stage when the cell’s nucleus divides and the copied chromosomes are separated into two sets. Cytokinesis is the step that follows and splits the cell into two daughter cells. These two processes work together to make sure each new cell receives genetic material and its own cytoplasm. Mitosis keeps the chromosome sets organized, while cytokinesis finishes the division of the whole cell. Together, they create two separate cells...

the cell cycle control system

Cell Cycle Checkpoints and Cyclin Control

The cell cycle is controlled by checkpoints that help a cell move from one phase to the next and begin mitosis. This control system uses internal regulatory molecules and outside signals to send stop or advance instructions. It makes sure each step is finished before the cell moves forward. Cyclins and cyclin-dependent kinases, or Cdks, are the main regulators of the cell cycle. They act during the G1, G2, and M phases. These regulators work at specific checkpoints to keep cell division...

molecular factors affecting cell division

molecular-factors-affecting-cell-division

Cell Cycle Regulators That Control Division

Cell division is controlled by outside signals and by internal cell cycle regulators. Nearby cell death can encourage division, and human growth hormone (hGH) can also promote it. In contrast, too little hGH or crowded cells can slow or stop division. Inside the cell, regulator molecules help each stage finish correctly before the next stage begins. Some regulators act directly on the cycle, while others affect the activity or production of other regulatory proteins. These molecules can either...

what is meiosis?

Meiosis and the Formation of Gametes

Meiosis is the cell division process that forms gametes, or sex cells. It reduces the chromosome number so offspring can inherit the correct amount of genetic material. This process includes two successive divisions. First, one cell divides, and then the resulting cells divide again. These steps separate the genetic material in a controlled way. Meiosis helps explain how sexual reproduction passes traits from one generation to the next. It is a key topic in high school biology because it...

overview of cell signaling

Cell Signaling Pathways and Responses

Cell signaling pathways and responses help cells communicate and react to changes. Cells send signals to one another, and those signals can trigger a specific response in the target cell. A signal usually begins when a signaling molecule reaches a cell with the right receptor, which is a protein that receives the message. The receptor helps the cell recognize the signal and start the communication process. Inside the cell, the message can move through a signaling pathway. This pathway passes...

types of signaling molecules

Chemical Messengers in Cell Signaling

Chemical messengers help cells communicate during signaling. These signaling molecules carry information from one cell to another and guide how cells respond. Some signaling molecules are gases, while others are proteins or peptides. Small lipids can also act as signals. In addition, cells may use steroids, amino acids, and even ions as signaling molecules. Each type of signaling molecule has different properties and works in a different way. Together, these molecules let cells send specific...

g protein-coupled receptors

G Protein-coupled Receptor Signaling

G protein-coupled receptors are a major class of cell-surface receptors. They help cells detect signals outside the cell and pass that information inward. These receptors are important in many kinds of cell communication. When a signal binds to a G protein-coupled receptor, the receptor changes shape. That change activates a G protein inside the cell. The activated G protein can then start a signaling pathway. This signaling system includes the receptor, the G protein, and the downstream...

cellular differentiation

From Stem Cell to Specialized Cells

Cellular differentiation turns unspecialized cells into specialized cells with specific jobs. This process helps a complex organism, such as a human, develop from a single fertilized egg into a body with many cell types. Nerve cells, muscle cells, and epithelial cells are examples of the final cell types that appear during development. A zygote is the first cell after fertilization. It is a totipotent stem cell, which means it has very high differentiation potential and can form all cell types...

key terms and concepts

Learn how cells control gene expression through transcription, RNA processing, RNA transport, translation, and protein modification, including ubiquitination.

How Cells Control Gene Expression | JoVE K12

anatomy and physiology

JoVE Core 解剖学と生理学では、人体の解剖学的および生理学的な詳細を、包括的で明確で魅力的なビデオ アニメーションで紹介します。このレッスン集は、人体の構造、コンポーネント、機能、要件に焦点を当てています。この知識を実際の医療および研究現場で応用することを実証する科学者による実際のビデオによって補完されています。

The Central Dogma

Replication in Eukaryotes

Types of RNA

Transcription

Translation

The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. ...

Construct an explanation of how the structures of DNA and RNA lead to the expression of information within the cell via the processes of replication, transcription, and translation

What is Meiosis?

Meiosis I

Meiosis is the division of a diploid cell into haploid cells forming sperm and eggs in animals through differentiation. Meiosis I is the first stage of ...

Meiosis II

Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for ...

Crossing over

Nondisjunction

Genome Copying Errors

DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a ...

Overview of DNA Repair

In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a ...

Base Excision Repair

One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and ...

RNA Editing

RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or ...

Mutations

Teratogenicity

The ability of a drug to produce structural deformations and functional abnormalities in the developing embryo or the fetus is called teratogenicity, and ...

Mechanisms of Retrovirus-induced Cancers

Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of ...

Construct an argument based on evidence to support the claim that inheritable genetic variations may result from:New genetic combinations through meiosis (crossing over, nondisjunction), Non-lethal errors occurring during replication (insertions, deletions, substitutions), Heritable mutations caused by environmental factors (radiation, chemicals, and viruses)

SB2.b

Transgenic Plants

Recombinant DNA technology called transgenesis is often used to add a foreign gene or remove a detrimental gene from an organism. Such genetically ...

Transgenic Organisms

Overview

Transgenic organisms are genetically engineered to carry transgenes&#x2014;genes from a different species&#x2014;as part of their genome. The ...

Testing For Genetically Modified Foods

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Genetic modification of foods has been a controversial issue due to debated ...

Genetic Engineering of Model Organisms

Transgenesis, or the use of genetic engineering to alter gene expression, is widely used in the field of developmental biology. Scientists use a number of ...

Ask questions to gather and communicate information about the use and ethical considerations of biotechnology in forensics, medicine, and agriculture

SB2.c

Obtain, evaluate, and communicate information to analyze how genetic information is expressed in cells

How Cells Control Gene Expression

Description

Transcript

Tags

More videos by Standards