Gene expression

rules by which information encoded within genetic material is translated into proteins

large family of RNA molecules that convey genetic information from DNA to the ribosome, where they specify the amino acid sequence of the protein products of gene expression

biosynthesis of RNA carried out on a template of DNA

cellular metabolic process in which a protein is formed, using the sequence of a mature mRNA or circRNA molecule to specify the sequence of amino acids in a polypeptide chain

in biology, the creation of proteins using information from nucleic acids

conversion of a gene's sequence into a mature gene product or products

An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word intron is derived from the term intragenic region, i.e., a region inside a gene. The term intron refers to both the DNA sequence within a gene and the corresponding RNA sequence in RNA transcripts. The non-intron sequences that become joined by this RNA processing to form the mature RNA are called exons.

region of DNA that initiates transcription of a particular gene

class of enzymes that synthesize RNA from a DNA template

any process of posttranscriptional gene inactivation mediated by small RNA molecules that may trigger mRNA degradation or down-regulate translation

thumb|350px|right|A typical operon In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product. The result of this is that the genes contained in the operon are either expressed together or not at all. Several genes must be co-transcribed to define an operon.

protein that binds to DNA and regulates gene expression by promoting or suppressing transcription

the process of removing sections of the primary RNA transcript to remove sequences not present in the mature form of the RNA and joining the remaining sections to form the mature form of the RNA

thumb|400px|Pre-miRNA instead of Pri-miRNA in the first point of mechanism. Diagram of microRNA (miRNA) action with mRNA thumb|400px|Examples of miRNA hairpins (stem-loops), with the mature miRNAs shown in red

DNA not coding for protein. Often translated to RNA and critical in regulating other genes

use of large set of oligonucleotide probes

process in which single-celled organisms monitor their population density by detecting the concentration of small, diffusible signal molecules produced by the cells themselves.

phenomenon that causes genes to be expressed in a parent-of-origin-specific manner

DNA sequence capable of binding activators

covalent and generally enzymatic modification of proteins during or after protein biosynthesis

A spliceosome is a large ribonucleoprotein (RNP) complex found primarily within the nucleus of eukaryotic cells. The spliceosome is assembled from small nuclear RNAs (snRNA) and numerous proteins. Small nuclear RNA (snRNA) molecules bind to specific proteins to form a small nuclear ribonucleoprotein complex (snRNP, pronounced "snurps"), which in turn combines with other snRNPs to form a large ribonucleoprotein complex called a spliceosome. The spliceosome removes introns from a transcribed pre-mRNA, a type of primary transcript. This process is generally referred to as splicing. An analogy is

process that modulates frequency, rate or extent of gene expression

a codon that marks the end of a sequence

set genes encoding proteins and enzymes for lactose metabolism

process of generating multiple mRNA molecules from a given set of exons by differential use of exons from the primary transcript(s), to form multiple mature mRNAs

processes by which an RNA primary transcript is chemically altered to produce a functional RNA molecule

chemical compound

DNA-dependent RNA polymerase

thumb|300x300px|The lac operon: '''1: RNA Polymerase, 2: [[lac repressor, 3: Promoter, 4: Operator, 5: Lactose, 6: lacZ, 7: lacY, 8: lacA.'''

genetic technique

thumb|430px|Typical structure of a mature eukaryotic mRNA

The transcriptome is the set of all RNA molecules (transcripts) in a cell or a population of cells. It includes all of the functional RNA molecules and all other transcripts that may arise by spurious transcription or transcription of non-functional regions such as pseudogenes or virus fragments. A major goal of modern molecular biology is to determine which transcripts are functional and which ones are junk RNA.

Non-coding regions on either end of mRNA

covalent alteration of one or more nucleotides within an RNA molecule to produce an RNA molecule with a sequence that differs from that coded genetically

biochemical material resulting from expression of a gene

short peptide (usually 16-30 amino acids long) present at the N-terminus of the majority of newly synthesized proteins that are destined towards the secretory pathway

process that prevents the expression of a gene

Demethylation is the chemical process resulting in the removal of a methyl group (CH3) from a molecule. A common way of demethylation is the replacement of a methyl group by a hydrogen atom, resulting in a net loss of one carbon and two hydrogen atoms.

class of proteins

enzyme that synthesizes RNA from an RNA template

section of genetic sequence that marks the end of gene or operon on genomic DNA for transcription

DNA sequence capable of binding repressors

mammalian protein found in Homo sapiens

collection of molecular regulators that interact with each other and with other substances in the cell to govern the gene expression levels of mRNA and proteins

thumb|419x419px|Summary of RNA-Seq. Within the organism, genes are transcribed and (in a eukaryote|eukaryotic organism) spliced to produce mature mRNA transcripts (red). The mRNA is extracted from the organism, fragmented and copied into stable ds-cDNA (blue). The ds-cDNA is sequenced using high-throughput, short-read sequencing methods. These sequences can then be aligned to a reference genome sequence to reconstruct which genome regions were being transcribed. This data can be used to annotate where expressed genes are, their relative expression levels, and any alternative splice variants.

free, online database and bioinformatics resource

biological signaling pathway

operon that codes for the components for production of tryptophan

gene which maintains basic cellular functions

compound which is analogous (structurally similar) to naturally occurring RNA and DNA, used in medicine and in molecular biology research

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor which in humans is encoded by the STAT3 gene. It is a member of the STAT protein family.

chemical compound

degrades mRNAs in which an amino-acid codon has changed to a nonsense codon

macromolecular complex containing both protein and RNA molecules.

prokaryotic protein

type of nucleic acid that affects the expression of associated genes

family of enzyme complexes

sequence at the 3' end of messenger RNA that does not code for product

region of a messenger RNA