mteb/BrightProPsychologyRetrieval huggingface dataset:
Translational regulation  

  Neomycin
 is an example of a small molecule that reduces
expression of all protein genes inevitably leading to cell death; it thus acts
as an  antibiotic  .

Main article:  Translation (genetics) 
"Translation \(genetics\)")

Direct regulation of translation is less prevalent than control of
transcription or mRNA stability but is occasionally used. Inhibition of
protein translation is a major target for  toxins  and
 antibiotics  , so they can kill a cell by
overriding its normal gene expression control.  Protein synthesis inhibitors
 include the
antibiotic  neomycin  and the toxin  ricin
 .
ValueRange(start=0, end=0)
This article includes a  list of references  ,  related reading
 , or  external
links  , **but its
sources remain unclear because it lacks inline citations

** .  Please help to  improve
 this article by  introducing
 more precise
citations.  _( October 2014  ) _ _(  Learn how and when to remove this
template message  ) _
* School Subjects
*  Mathematics 
*  Physics 
*  Chemistry 
*  Biology 
*  Social Science 
*  English Grammar 
*  World GK
##  Some examples  ¶
*  Algebraic closure 
*  Algebraic expression 
*  Analytic expression 
*  Closed-form expression 
*  Combinator 
*  Computer algebra expression 
*  Defined and undefined 
*  Equation 
*  Expression (programming)  "Expression \(programming\)")
*  Formal grammar 
*  Formula 
*  Functional programming 
*  Logical expression 
*  Term (logic)  "Term \(logic\)")
*  Well-defined expression 
*  Number sentence
###  ` Subquery()  ` expressions  ¶
See also  

*  AlloMap molecular expression testing 
*  Bookmarking 
*  EPIC-Seq 
*  Expressed sequence tag 
*  Expression Atlas 
*  Expression profiling 
*  Gene structure 
*  Genetic engineering 
*  Genetically modified organism 
*  List of biological databases 
*  List of human genes 
*  Oscillating gene 
*  Paramutation 
*  Protein production 
*  Protein purification 
*  Ribonomics 
*  Ridge  "Ridge \(biology\)")
*  Sequence profiling tool 
*  Transcriptional bursting 
*  Transcriptional noise 
*  Transcript of unknown function
Maps  "Map \(mathematics\)") and  cardinality
 |
The use of expressions ranges from the simple:
For example, if the expression  x  /  y  {\displaystyle x/y}

is evaluated with  _x_ = 10, _y_ = 5  , it evaluates to 2; this is denoted
Something went wrong. Wait a moment and try again.
Folding  

Main article:  Protein folding 

 Protein before (left)
and after (right) folding

Each  protein  exists as an unfolded  polypeptide
 or random coil when translated from a
sequence of  mRNA  into a linear chain of  amino acids
 . This polypeptide lacks any developed three-
dimensional structure (the left hand side of the neighboring figure). The
polypeptide then folds into its characteristic and functional  three-
dimensional structure  from a 
random coil  .  [15]  Amino acids interact
with each other to produce a well-defined three-dimensional structure, the
folded protein (the right hand side of the figure) known as the  native state
 . The resulting three-dimensional
structure is determined by the amino acid sequence (  Anfinsen's dogma
 ).  [16]

The correct three-dimensional structure is essential to function, although
some parts of functional proteins  may remain unfolded

.  [17]  Failure to fold into the intended shape usually produces inactive
proteins with different properties including toxic  prions  . Several  neurodegenerative  and other  diseases  are
believed to result from the accumulation of _misfolded_ proteins.  [18]  Many
 allergies  are caused by the folding of the
proteins, for the immune system does not produce antibodies for certain
protein structures.  [19]

Enzymes called  chaperones  "Chaperone
\(protein\)") assist the newly formed protein to attain (  fold
 into) the 3-dimensional structure
it needs to function.  [20]  Similarly, RNA chaperones help RNAs attain their
functional shapes.  [21]  Assisting protein folding is one of the main roles
of the endoplasmic reticulum in eukaryotes.
|   Traditional  |
###  Syntax  &action=edit&section=4 "Edit
section: Syntax") ]
##  Output field  ¶
External links  

*  Plant Transcription Factor Database and Plant Transcriptional Regulation Data and Analysis Platform 

*  v  
*  t  
*  e  

Gene expression

---
 Introduction
to genetics  |

*  Genetic code 
*  Central dogma 
*  DNA  →  RNA  →  Protein 
* [ Special transfers ](/wiki/Central_dogma_of_molecular_biology
*  Alphabet  "Alphabet \(formal languages\)")
*  Arity 
*  Automata 
*  Axiom schema 
* Expression
*  ground 
*  Extension 
*  by definition 
*  conservative 
*  Relation 
*  Formation rule 
*  Grammar 
*  Formula 
*  atomic 
*  closed  "Sentence \(mathematical logic\)")
*  ground 
*  open 
*  Free/bound variable 
*  Language 
*  Metalanguage 
*  Logical connective 
*  ¬ 
*  ∨ 
*  ∧ 
*  → 
*  ↔ 
*  = 
*  Predicate  "Predicate \(mathematical logic\)")
*  functional 
*  variable 
*  propositional variable 
*  Proof 
*  Quantifier  "Quantifier \(logic\)")
*  ∃ 
*  ! 
*  ∀ 
*  rank 
*  Sentence  "Sentence \(mathematical logic\)")
*  atomic 
*  spectrum 
*  Signature  "Signature \(logic\)")
*  String  "String \(formal languages\)")
*  Substitution  "Substitution \(logic\)")
*  Symbol  "Symbol \(formal\)")
*  function 
*  logical/constant 
*  non-logical 
*  variable  "Variable \(mathematics\)")
*  Term  "Term \(logic\)")
*  Theory  "Theory \(mathematical logic\)")
*  list
∑  n  =  1  3  (  2  n  x  )  ,  {\displaystyle \sum _{n=1}^{3}(2nx),}
Join the community on the Django Forum.
 Ticket tracker
* of  arithmetic  :
*  Peano 
*  second-order 
*  elementary function 
*  primitive recursive 
*  Robinson 
*  Skolem 
* of the  real numbers 
*  Tarski's axiomatization 
* of  Boolean algebras 
*  canonical 
*  minimal axioms 
* of  geometry  :
*  Euclidean  :
*  _Elements_ 
*  Hilbert's 
*  Tarski's 
*  non-Euclidean
##  Practice
##  Support Us
Translocation  

Secretory proteins of eukaryotes or prokaryotes must be translocated to enter
the secretory pathway. Newly synthesized proteins are directed to the
eukaryotic Sec61 or prokaryotic SecYEG translocation channel by  signal
peptides  . The efficiency of protein
secretion in eukaryotes is very dependent on the  signal peptide
 which has been used.  [22]
Set theory  |
` contains_aggregate  ` ¶
DNA methylation and demethylation in transcriptional regulation  

 DNA methylation is
the addition of a  methyl  group to the DNA that
happens at  cytosine  . The image shows a
cytosine single ring base and a methyl group added on to the 5 carbon. In
mammals, DNA methylation occurs almost exclusively at a cytosine that is
followed by a  guanine  .

 DNA methylation  is a widespread
mechanism for epigenetic influence on gene expression and is seen in 
bacteria  and  eukaryotes  and has roles in heritable transcription silencing and
transcription regulation. Methylation most often occurs on a cytosine (see
Figure). Methylation of cytosine primarily occurs in dinucleotide sequences
where a cytosine is followed by a guanine, a  CpG site  . The number of  CpG sites  in the human
genome is about 28 million.  [43]  Depending on the type of cell, about 70% of
the CpG sites have a methylated cytosine.  [44]

Methylation of cytosine in DNA has a major role in regulating gene expression.
Methylation of CpGs in a promoter region of a gene usually represses gene
transcription  [45]  while methylation of CpGs in the body of a gene increases
expression.  [46]   TET enzymes  play a
central role in demethylation of methylated cytosines. Demethylation of CpGs
in a gene promoter by  TET enzyme  activity
increases transcription of the gene.  [47]
*  Languages 
*  Python 
*  Java 
*  C++ 
*  PHP 
*  GoLang 
*  SQL 
*  R Language 
*  Android Tutorial 
*  Tutorials Archive
##  Examples  &action=edit&section=1 "Edit
section: Examples") ]
*  Python Tutorial 
*  Python Programming Examples 
*  Python Projects 
*  Python Tkinter 
*  Web Scraping 
*  OpenCV Tutorial 
*  Python Interview Question
from django.db.models import Aggregate
---
Example  axiomatic
systems  (  list
 )  |
* Prev: [ Lookup API reference ](../lookups/)
* Next: [ Conditional Expressions ](../conditional-expressions/)
*  Table of contents 
*  General Index 
*  Python Module Index
In  algebra  , an expression may be used to
designate a value, which might depend on values assigned to  variables
 "Variable \(mathematics\)") occurring in the
expression. The determination of this value depends on the  semantics
 attached to the symbols of the expression. The
choice of semantics depends on the context of the expression. The same
syntactic expression _1 + 2 × 3_ can have different values (mathematically 7,
but also 9), depending on the  order of operations
 implied by the context (See
also  Operations § Calculators  ).
* This page was last edited on 24 March 2024, at 17:51  (UTC)  .
* Text is available under the  Creative Commons Attribution-ShareAlike License 4.0   ; additional terms may apply. By using this site, you agree to the  Terms of Use  and  Privacy Policy  . Wikipedia® is a registered trademark of the  Wikimedia Foundation, Inc.  , a non-profit organization.
The equivalence of two lambda expressions is  undecidable
 . This is also the case for the
expressions representing real numbers, which are built from the integers by
using the arithmetical operations, the logarithm and the exponential ( 
Richardson's theorem  ).
Inducible expression  

 Doxycycline  is also used in "Tet-on" and
"Tet-off"  tetracycline controlled transcriptional activation
 to regulate  transgene
 expression in organisms and  cell cultures
 .
Protein transport  

Many proteins are destined for other parts of the cell than the cytosol and a
wide range of signalling sequences or  (signal peptides)
 are used to direct proteins to where
they are supposed to be. In prokaryotes this is normally a simple process due
to limited compartmentalisation of the cell. However, in eukaryotes there is a
great variety of different targeting processes to ensure the protein arrives
at the correct organelle.

Not all proteins remain within the cell and many are exported, for example, 
digestive enzymes  ,  hormones
 and  extracellular matrix
 proteins. In eukaryotes
the export pathway is well developed and the main mechanism for the export of
these proteins is translocation to the endoplasmic reticulum, followed by
transport via the  Golgi apparatus 
.  [23]  [24]
from django.db.models.functions import Length
Gene expression databases  

*  Gene expression omnibus  (GEO) at  NCBI  [81]
*  Expression Atlas  at the  EBI 
*  Bgee   Bgee  at the  SIB Swiss Institute of Bioinformatics 
* Mouse  Gene Expression Database  at the  Jackson Laboratory 
*  CollecTF  : a database of experimentally validated transcription factor-binding sites in Bacteria.  [82]
* COLOMBOS: collection of bacterial expression compendia.  [83]
*  Many Microbe Microarrays Database  : microbial Affymetrix data  [84]
###  ` F()  ` expressions  ¶
*  Home 
*  Saved Videos  
*  Courses 
* ##  Data Structures and Algorithms
*  Getting Help FAQ 
* [ #django IRC channel ](irc://irc.libera.chat/django)
*  Django Discord 
*  Official Django Forum
On PostgreSQL, the SQL looks like:
Predicate  |
3  \+  8  {\displaystyle 3+8}
###  Please _ Login  _ to comment...
####  Using ` F()  ` with annotations  ¶
*  el 
*  es 
*  fr 
*  id 
*  it 
*  ja 
*  ko 
*  pl 
*  pt-br 
*  zh-hans 
* Language: **en**
##  Learn More
#  Additional Information
* Free Online Tools
*  Typing Test 
*  Image Editor 
*  Code Formatters 
*  Code Converters 
*  Currency Converter 
*  Random Number Generator 
*  Random Password Generator
*  Abstract algebra 
*  Logical expressions 
*  Elementary algebra
mRNA-protein correlation  

While transcription directly reflects gene expression, the copy number of mRNA
molecules does not directly correlate with the number of protein molecules
translated from mRNA. Quantification of both protein and mRNA permits a
correlation of the two levels. Regulation on each step of gene expression can
impact the correlation, as shown for regulation of translation  [13]  or
protein stability.  [72]  Post-translational factors, such as protein
transport in highly polar cells,  [73]  can influence the measured mRNA-
protein correlation as well.
__ Menu
Formal systems  (  list
 ),
 language  and  syntax
 "Syntax \(logic\)") |
*  Will Pimblett donated to the Django Software Foundation to support Django development. Donate today!
Model theory  |
#  Django Links
*  expression-evaluation 
*  C++ Programs 
*  DSA 
*  Mathematical 
*  School Programming
Explore More
For a given combination of values for the free variables, an expression may be
evaluated, although for some combinations of values of the free variables, the
value of the expression may be undefined. Thus an expression represents a 
function  "Function \(mathematics\)") whose
inputs are the values assigned to the free variables and whose output is the
resulting value of the expression.
**Example:**
shifts one bit position to right.
Both classes return SQL with the template:
##  Get Help
*  JavaScript 
*  JavaScript Examples 
*  TypeScript 
*  ReactJS 
*  NextJS 
*  AngularJS 
*  NodeJS 
*  Lodash 
*  Web Browser
The semantic rules may declare that certain expressions do not designate any
value (for instance when they involve division by 0); such expressions are
said to have an undefined value, but they are well-formed expressions
nonetheless. In general the meaning of expressions is not limited to
designating values; for instance, an expression might designate a condition,
or an  equation  that is to be solved, or it can
be viewed as an object in its own right that can be manipulated according to
certain rules. Certain expressions that designate a value simultaneously
express a condition that is assumed to hold, for instance those involving the
operator  ⊕  {\displaystyle \oplus }  
to designate an internal  direct sum  .
* Company
*  About Us 
*  Legal 
*  Careers 
*  In Media 
*  Contact Us 
*  Advertise with us 
*  GFG Corporate Solution 
*  Placement Training Program
f  (  a  )  \+  ∑  k  =  1  n  1  k  !  d  k  d  t  k  |  t  =  0  f  (  u  (  t  )  )  \+  ∫  0  1  (  1  −  t  )  n  n  !  d  n  \+  1  d  t  n  \+  1  f  (  u  (  t  )  )  d  t  .  {\displaystyle f(a)+\sum _{k=1}^{n}\left.{\frac {1}{k!}}{\frac {d^{k}}{dt^{k}}}\right|_{t=0}f(u(t))+\int _{0}^{1}{\frac {(1-t)^{n}}{n!}}{\frac {d^{n+1}}{dt^{n+1}}}f(u(t))\,dt.}
#  Query Expressions  ¶
*  DevOps 
*  Git 
*  AWS 
*  Docker 
*  Kubernetes 
*  Azure 
*  GCP 
*  DevOps Roadmap
Theorems (  list  )
and  paradoxes  |
5, 10 + 5 / 6.0, 'x’
queryset.annotate(field_lower=Lower("field"))
####  Using ` F()  ` with logical operations  ¶
We use cookies to ensure you have the best browsing experience on our website.
By using our site, you acknowledge that you have read and understood our 
_Cookie Policy_  &  _Privacy
Policy_  Got It !
##  Follow Us
*  Computer Science 
*  Operating Systems 
*  Computer Network 
*  Database Management System 
*  Software Engineering 
*  Digital Logic Design 
*  Engineering Maths
*  Article   "View the content page \[c\]")
*  Talk   "Discuss improvements to the content page \[t\]")
Add Your Comment
Like Article  __
Expression system  

 Tet-ON inducible shRNA system

Main article:  Protein production (biotechnology)
 "Protein production
\(biotechnology\)")

An expression system is a system specifically designed for the production of a
gene product of choice. This is normally a protein although may also be RNA,
such as  tRNA  or a  ribozyme  . An expression system consists of a gene, normally encoded by 
DNA  , and the  molecular machinery
 required to  transcribe
 "Transcription \(genetics\)") the DNA into
 mRNA  and  translate  the
mRNA into  protein  using the reagents provided. In
the broadest sense this includes every living cell but the term is more
normally used to refer to expression as a laboratory tool. An expression
system is therefore often artificial in some manner. Expression systems are,
however, a fundamentally natural process. Viruses are an excellent example
where they replicate by using the host cell as an expression system for the
viral proteins and genome.
Building Expression tree from Prefix Expression
  Convert Infix expression to Postfix expression
  Python | Set 2 (Variables, Expressions, Conditions and
Functions)    Clarity and Simplicity of Expressions
 
Match a pattern and String without using regular expressions
  Infix, Postfix and Prefix Expressions/Notations
  Evaluation
of Prefix Expressions    Extracting email addresses using regular expressions in Python
  Regular Expressions to Validate Google Analytics
Tracking Id    Balanced expressions such that given
positions have opening brackets | Set 2
Tells Django which value should be returned when the expression is used to
apply a function over an empty result set. Defaults to  ` NotImplemented  `
") which forces the expression to be computed on the database.
*  1.8 
*  1.10 
*  1.11 
*  2.0 
*  2.1 
*  2.2 
*  3.0 
*  3.1 
*  3.2 
*  4.0 
*  4.1 
*  4.2 
*  dev 
* Documentation version: **5.0**
%(frame_type)s BETWEEN %(start)s AND %(end)s
Search:  __ Search
Regulation of gene expression  

Main article:  Regulation of gene expression

 The patchy
colours of a  tortoiseshell cat  are the result of different levels of expression of  pigmentation
 genes in different areas of
the  skin  .

Regulation of gene expression is the control of the amount and timing of
appearance of the functional product of a gene. Control of expression is vital
to allow a cell to produce the gene products it needs when it needs them; in
turn, this gives cells the flexibility to adapt to a variable environment,
external signals, damage to the cell, and other stimuli. More generally, gene
regulation gives the cell control over all structure and function, and is the
basis for  cellular differentiation  ,  morphogenesis  and the versatility and adaptability of any organism.

Numerous terms are used to describe types of genes depending on how they are
regulated; these include:

* A **constitutive gene** is a gene that is transcribed continually as opposed to a facultative gene, which is only transcribed when needed.
* A _ housekeeping gene  _ is a gene that is required to maintain basic cellular function and so is typically expressed in all cell types of an organism. Examples include  actin  ,  GAPDH  and  ubiquitin  . Some housekeeping genes are transcribed at a relatively constant rate and these genes can be used as a reference point in experiments to measure the expression rates of other genes.
* A **facultative gene** is a gene only transcribed when needed as opposed to a constitutive gene.
* An **inducible gene** is a gene whose expression is either responsive to environmental change or dependent on the position in the cell cycle.

Any step of gene expression may be modulated, from the DNA-RNA transcription
step to  post-translational modification  of a protein.
The stability of the final gene product, whether it is RNA or protein, also
contributes to the expression level of the gene—an unstable product results in
a low expression level. In general gene expression is regulated through
changes  [25]  in the number and type of interactions between molecules  [26]
that collectively influence transcription of DNA  [27]  and translation of
RNA.  [28]

Some simple examples of where gene expression is important are:

* Control of  insulin  expression so it gives a signal for  blood glucose regulation  .
*  X chromosome inactivation  in female  mammals  to prevent an "overdose" of the genes it contains.
*  Cyclin  expression levels control progression through the eukaryotic  cell cycle  .
x  y  |  x  =  10  ,  y  =  5  =  2\.  {\displaystyle \left.{\frac {x}{y}}\right|_{x=10,\,y=5}=2.}
---
Types of  sets  "Set \(mathematics\)") |
Toggle theme (current theme: auto)
*  Overview 
*  Download 
*  Documentation 
*  News 
*  Community 
*  Code 
*  Issues 
*  About 
*  ♥ Donate 
* Toggle theme (current theme: auto)
to the complex:
##  You are here:
identifiers "Edit this at Wikidata") |

*  France 
*  BnF data 
*  Germany 
*  Israel 
*  United States 
*  Czech Republic 

---|---

Retrieved from " 
https://en.wikipedia.org/w/index.php?title=Gene_expression&oldid=1215743315

"

 Categories  :

*  Gene expression 
*  Molecular biology 

Hidden categories:

*  CS1 maint: location missing publisher 
*  Articles with short description 
*  Short description matches Wikidata 
*  Articles with excerpts 
*  Articles needing additional references from February 2020 
*  All articles needing additional references 
*  Articles with BNF identifiers 
*  Articles with BNFdata identifiers 
*  Articles with GND identifiers 
*  Articles with J9U identifiers 
*  Articles with LCCN identifiers 
*  Articles with NKC identifiers 

* This page was last edited on 26 March 2024, at 21:27  (UTC)  .
* Text is available under the  Creative Commons Attribution-ShareAlike License 4.0   ; additional terms may apply. By using this site, you agree to the  Terms of Use  and  Privacy Policy  . Wikipedia® is a registered trademark of the  Wikimedia Foundation, Inc.  , a non-profit organization.

*  Privacy policy 
*  About Wikipedia 
*  Disclaimers 
*  Contact Wikipedia 
*  Code of Conduct 
*  Developers 
* [ Statistics ](https://stats.wikimedia.org/
x > y && x == 10, x == 10 || y == 5
*  Sponsor Django 
*  Corporate membership 
*  Official merchandise store 
*  Benevity Workplace Giving Program
###  ` Value()  ` expressions  ¶
###  Raw SQL expressions  ¶
Repressor "Lambda phage") transcription
factor (green) binds as a dimer to  major groove
 of DNA target
(red and blue) and disables initiation of transcription. From   PDB
 :  1LMB
 ​.

Direct interaction with DNA is the simplest and the most direct method by
which a protein changes transcription levels. Genes often have several protein
binding sites around the coding region with the specific function of
regulating transcription. There are many classes of regulatory DNA binding
sites known as  enhancers  "Enhancer
\(genetics\)") ,  insulators  "Insulator
\(genetics\)") and  silencers  "Silencer
\(genetics\)") . The mechanisms for regulating transcription are varied, from
blocking key binding sites on the DNA for  RNA polymerase
 to acting as an  activator
 "Activator \(genetics\)") and promoting
transcription by assisting RNA polymerase binding.

The activity of transcription factors is further modulated by intracellular
signals causing protein post-translational modification including 
phosphorylation  ,  acetylation
 , or  glycosylation  . These changes influence a transcription factor's ability to
bind, directly or indirectly, to promoter DNA, to recruit RNA polymerase, or
to favor elongation of a newly synthesized RNA molecule.

The nuclear membrane in eukaryotes allows further regulation of transcription
factors by the duration of their presence in the nucleus, which is regulated
by reversible changes in their structure and by binding of other proteins.
[29]  Environmental stimuli or endocrine signals  [30]  may cause modification
of regulatory proteins  [31]  eliciting cascades of intracellular signals,
[32]  which result in regulation of gene expression.

It has become apparent that there is a significant influence of non-DNA-
sequence specific effects on transcription. These effects are referred to as 
epigenetic  and involve the higher order
structure of DNA, non-sequence specific DNA binding proteins and chemical
modification of DNA. In general epigenetic effects alter the accessibility of
DNA to proteins and so modulate transcription.

 In eukaryotes, DNA
is organized in form of  nucleosomes  .
Note how the DNA (blue and green) is tightly wrapped around the protein core
made of  histone   octamer  (ribbon coils), restricting access to the DNA. From   PDB
 :  1KX5
 ​.

In eukaryotes the structure of  chromatin  ,
controlled by the  histone code  ,
regulates access to DNA with significant impacts on the expression of genes in
 euchromatin  and  heterochromatin
 areas.
* Data Science & ML
*  Data Science With Python 
*  Data Science For Beginner 
*  Machine Learning Tutorial 
*  ML Maths 
*  Data Visualisation Tutorial 
*  Pandas Tutorial 
*  NumPy Tutorial 
*  NLP Tutorial 
*  Deep Learning Tutorial