dominant negative

zzc2211

Dominant negative mutation1 ?* \8 D7 a3 Z" v' l$ h8 L
Definition(s)
7 {3 ^' O0 _3 m! TA mutation whose gene product adversely affects the normal, wild-type gene product within the same cell, usually by dimerizing (combining) with it. In cases of polymeric molecules, such as collagen, dominant negative mutations are often more deleterious than mutations causing the production of no gene product (null mutations or null alleles).
1 n9 e3 Z3 ]( k+ v4 D0 [Definition from: GeneTests from the University of Washington and the National Center for Biotechnology Information
/ p+ [$ H/ N/ K% ]2 g- F9 I5 E
1 v  @1 @, n9 R6 w1 S$ M# dDominant negative mutations (also called antimorphic mutations) have an altered gene product that acts antagonistically to the wild-type allele. These mutations usually result in an altered molecular function (often inactive) and are characterised by a dominant or semi-dominant phenotype.
0 ?" I* M& L$ N! x0 P& P& R2 U* a, M
Definition of dominant negative :/ d2 q% c+ q" r% `0 \; b1 v
A mutation whose gene product adversely affects the normal, wild-type gene product within the same cell. This usually occurs if the product can still interact with the same elements as the wild-type product, but block some aspect of its function.
4 @0 T$ @& u3 V) mExamples:
% j( e5 R: [! r7 Z1. A mutation in a transcription factor that removes the activation domain, but still contains the DNA binding domain. This product can then block the wild-type transcription factor from binding the DNA site leading to reduced levels of gene activation., W) q- T1 B% W& l4 n% u6 w
2. A protein that is functional as a dimer. A mutation that removes the functional domain, but retains the dimerization domain would cause a dominate negative phenotype, because some fraction of protein dimers would be missing one of the functional domains.
0 F; o. l! w# N; k9 N1 c( Q4 k! b' t! h" k. b; s" ~, L% K
dominant negative effect
, p5 ?4 s2 P  X2 P! ]7 B3 {显性负效应：某些信号转导蛋白突变后不仅自身无功能，还能抑制或阻断同一细胞内的野生型信号转导蛋白的作用，这种作用被称为显性负效应。具有显性负效应的突变体被称为显性负性突变体（dominant negative mutant)。机理是突变型蛋白和相关蛋白形成无功能的二聚体，野生型蛋白功能被抑制。2 y- w0 g' ^$ L* T$ Y' g5 T9 E: j

zzc2211

Dominant negative mutation
: w) m) F! |# H) PDefinition(s)
' z) M  T: u+ C% `, q* sA mutation whose gene product adversely affects the normal, wild-type gene product within the same cell, usually by dimerizing (combining) with it. In cases of polymeric molecules, such as collagen, dominant negative mutations are often more deleterious than mutations causing the production of no gene product (null mutations or null alleles).
2 I+ q3 h) D; u- x3 O* d; C. uDefinition from: GeneTests from the University of Washington and the National Center for Biotechnology Information
7 q$ e% }6 j& G& O- s8 q$ R( W& H
9 E( S* w- S7 d. K4 UDominant negative mutations (also called antimorphic mutations) have an altered gene product that acts antagonistically to the wild-type allele. These mutations usually result in an altered molecular function (often inactive) and are characterised by a dominant or semi-dominant phenotype.
2 {" i+ P1 F/ j; h6 ^5 h6 R# ?. y) h1 t  U* F) R# C* n; C
Definition of dominant negative :
$ g5 _6 C4 p5 V# T1 TA mutation whose gene product adversely affects the normal, wild-type gene product within the same cell. This usually occurs if the product can still interact with the same elements as the wild-type product, but block some aspect of its function.# O1 G" \: b8 _# [) v, i
Examples: 0 W+ u5 y/ F5 G0 m2 @  B6 s7 d
1. A mutation in a transcription factor that removes the activation domain, but still contains the DNA binding domain. This product can then block the wild-type transcription factor from binding the DNA site leading to reduced levels of gene activation.' L; g; U. b" r7 H
2. A protein that is functional as a dimer. A mutation that removes the functional domain, but retains the dimerization domain would cause a dominate negative phenotype, because some fraction of protein dimers would be missing one of the functional domains.
( N6 @$ _/ m( \# d2 V
% _3 k# o( K, P/ b6 p9 v5 Y& Fdominant negative effect
3 y; r/ r% P& s/ H2 y, t7 w显性负效应：某些信号转导蛋白突变后不仅自身无功能，还能抑制或阻断同一细胞内的野生型信号转导蛋白的作用，这种作用被称为显性负效应。具有显性负效应的突变体被称为显性负性突变体（dominant negative mutant)。机理是突变型蛋白和相关蛋白形成无功能的二聚体，野生型蛋白功能被抑制。2 }/ P5 y: g; O3 A7 b