scholarly journals Synthetic Point Mutagenesis

10.5772/35920 ◽  
2012 ◽  
Author(s):  
Roman A.G. ◽  
Joke J.F.A. van Vugt ◽  
Colin Logie
Keyword(s):  
Point Mutagenesis

Regulation of the junB gene by v-src

1992 ◽  
Vol 12 (8) ◽  
pp. 3356-3364
Author(s):  
I Apel ◽  
C L Yu ◽  
T Wang ◽  
C Dobry ◽  
M E Van Antwerp ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Gene Products ◽  
3T3 Cells ◽  
Tyrosine Kinase Activity ◽  
Basal Expression ◽  
High Level ◽  
Transformed Cell Lines ◽  
Point Mutagenesis ◽  
Nih 3T3 ◽  
Nucleotide Region

The proteins encoded by cellular and viral src genes are believed to be involved in the transmission of mitogenic signals, the nuclear recipients of which are largely unknown. In this work, we report that four different v-src-transformed cell lines from three different species possess elevated levels of junB transcripts. Transient expression of junB promoter-chloramphenicol acetyltransferase constructs in NIH 3T3 cells was used to demonstrate that the increase in junB transcripts was specifically associated with v-src expression and could not be recapitulated with a c-src, v-H-ras, or v-raf expression vector. Deletion mutants were used to localize the v-src-responsive region in the junB promoter to a 121-nucleotide region encompassing the CCAAT and TATAA elements. This region is distinct from one in the 5' untranslated region of the junB gene which is required to maintain its high-level basal expression. Point mutagenesis of the junB TATAA box completely abolished v-src responsiveness, suggesting that proteins which bind to this element are modified by src transformation. Several v-src and c-src mutants were used to demonstrate that elevated tyrosine kinase activity of src proteins is required for the observed effects on junB expression. Finally, homology between the TATAA box regions of junB and the unrelated but src-responsive gene 9E3/CEF-4 suggests that modulation of gene activity through proteins which bind to this region may be a recurrent, although not exclusive, theme in src transforming action. Our results suggest that src proteins may modulate some nuclear effectors through pathways not involving cellular ras or raf gene products.

[14] Polymerase chain reaction-based point mutagenesis protocol

1993 ◽  
pp. 218-227 ◽  
Author(s):  
L.-. Zhao ◽  
Q.X. Zhang ◽  
R. Padmanabhan
Keyword(s):  
Polymerase Chain Reaction ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Point Mutagenesis

Architecture of the maize mitochondrial atp1 promoter as determined by linker-scanning and point mutagenesis

1993 ◽  
Vol 13 (12) ◽  
pp. 7232-7238
Author(s):  
W D Rapp ◽  
D S Lupold ◽  
S Mack ◽  
D B Stern
Keyword(s):  
Promoter Region ◽  
Consensus Sequence ◽  
Point Mutations ◽  
In Vitro Transcription ◽  
Wild Type ◽  
Transcription Start ◽  
Transcription System ◽  
Mitochondrial Promoters ◽  
Point Mutagenesis

Plant mitochondrial promoters are poorly conserved but generally share a loose consensus sequence spanning approximately 17 nucleotides. Using a homologous in vitro transcription system, we have previously shown that an 11-nucleotide sequence within this region comprises at least part of the maize mitochondrial atp1 promoter (W. Rapp and D. Stern, EMBO J. 11:1065-1073, 1992). We have extended this finding by using a series of linker-scanning and point mutations to define the atp1 promoter in detail. Our results show that mutations at positions -12 to +5, relative to the major transcription start site, can decrease initiation rates to between < 10 and 40% of wild-type levels. Some mutations, scattered throughout this region, have lesser effects or no effect. Taken together, our data suggest a model in which the atp1 promoter consists of a central domain extending from -7 to +5 and an upstream domain of 1 to 3 bp that is centered around -11 to -12. Because many mutations within this promoter region are tolerated in vitro, the maize atp1 promoter is distinct from the highly conserved yeast mitochondrial promoters.

Polymerase Chain Reaction-Based Point Mutagenesis Protocol

1995 ◽  
pp. 323-332 ◽  
Author(s):  
L.-J. ZHAO ◽  
Q.X. ZHANG ◽  
R.P. ADMANABHAN
Keyword(s):  
Polymerase Chain Reaction ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Point Mutagenesis

Random Changes of Amino Acid Residues with Expected Frequency by Saturated Point Mutagenesis

2000 ◽  
Vol 10 (2) ◽  
pp. 232-235 ◽  
Author(s):  
Seong Joong Kim ◽  
Hweon Park ◽  
Jeong-Kook Kim ◽  
Jae Yung Lee ◽  
Kwangseog Ahn ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Residues ◽  
Expected Frequency ◽  
Point Mutagenesis

Differential involvement of the related DNA helicases Pif1p and Rrm3p in mtDNA point mutagenesis and stability

Gene ◽  
2005 ◽  
Vol 354 ◽  
pp. 86-92 ◽  
Author(s):  
Thomas W. O'Rourke ◽  
Nicole A. Doudican ◽  
Hong Zhang ◽  
Jana S. Eaton ◽  
Paul W. Doetsch ◽  
...  
Keyword(s):  
Dna Helicases ◽  
Differential Involvement ◽  
Point Mutagenesis

scholarly journals Different classes of polyadenylation sites in the yeast Saccharomyces cerevisiae.

1991 ◽  
Vol 11 (6) ◽  
pp. 3060-3069 ◽  
Author(s):  
S Irniger ◽  
C M Egli ◽  
G H Braus
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Gene ◽  
Signal Sequence ◽  
Test System ◽  
Dependent Manner ◽  
Yeast Saccharomyces Cerevisiae ◽  
Sequence Elements ◽  
Polyadenylation Sites ◽  
Point Mutagenesis

This report provides an analysis of the function of polyadenylation sites from six different genes of the yeast Saccharomyces cerevisiae. These sites were tested for their ability to turn off read-through transcription into the URA3 gene in vivo when inserted into an ACT-URA3 fusion gene. The 3' ends of all polyadenylation sites inserted into the test system in their natural configuration are identical to the 3' ends of the chromosomal genes. We identified two classes of polyadenylation sites: (i) efficient sites (originating from the genes GCN4 and PHO5) that were functional in a strict orientation-dependent manner and (ii) bidirectional sites (derived from ARO4, TRP1, and TRP4) that had a distinctly reduced efficiency. The ADH1 polyadenylation site was efficient and bidirectional and was shown to be a combination of two polyadenylation sites of two convergently transcribed genes. Sequence comparison revealed that all efficient unidirectional polyadenylation sites contain the sequence TTTTTAT, whereas all bidirectional sites have the tripartite sequence TAG...TA (T)GT...TTT. Both sequence elements have previously been proposed to be involved in 3' end formation. Site-directed point mutagenesis of the TTTTTAT sequence had no effect, whereas mutations within the tripartite sequence caused a reduced efficiency for 3' end formation. The tripartite sequence alone, however, is not sufficient for 3' end formation, but it might be part of a signal sequence in the bidirectional class of yeast polyadenylation sites. Our findings support the assumption that there are at least two different mechanisms with different sequence elements directing 3' end formation in yeast.

scholarly journals Rotaviruses interact with α4β7 and α4β1 integrins by binding the same integrin domains as natural ligands

2005 ◽  
Vol 86 (12) ◽  
pp. 3397-3408 ◽  
Author(s):  
Kate L. Graham ◽  
Fiona E. Fleming ◽  
Peter Halasz ◽  
Marilyn J. Hewish ◽  
Hadya S. Nagesha ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Virus Binding ◽  
Group A Rotaviruses ◽  
Intestinal Pathogens ◽  
Integrin Ligand ◽  
Surface Loops ◽  
Point Mutagenesis ◽  
Cell Adhesion Molecule 1

Group A rotaviruses are major intestinal pathogens that express potential α4β1 and α4β7 integrin ligand sequences Leu–Asp–Val and Leu–Asp–Ile in their outer capsid protein VP7, and Ile–Asp–Ala in their spike protein VP4. Monkey rotavirus SA11 can use recombinant α4β1 as a cellular receptor. In this study a new potential α4β1, α4β7 and α9β1 integrin ligand sequence, Tyr–Gly–Leu, was identified in VP4. It was shown that several human and monkey rotaviruses bound α4β1 and α4β7, but not α9β1. Binding to α4β1 mediated the infectivity and growth of monkey rotaviruses, and binding to α4β7 mediated their infectivity. A porcine rotavirus interacted with α4 integrins at a post-binding stage to facilitate infection. Activation of α4β1 increased rotavirus infectivity. Cellular treatment with peptides containing the α4 integrin ligand sequences Tyr–Gly–Leu and Ile–Asp–Ala eliminated virus binding to α4 integrins and infectivity. In contrast, rotavirus recognition of α4 integrins was unaffected by a peptide containing the sequence Leu–Asp–Val or by a mutation in the VP7 Leu–Asp–Val sequence. VP4 involvement in rotavirus recognition of α4β1 was demonstrated with rotavirus reassortants. Swapping and point mutagenesis of α4 surface loops showed that rotaviruses required the same α4 residues and domains for binding as the natural α4 integrin ligands: mucosal addressin cell adhesion molecule-1, fibronectin and vascular cell adhesion molecule-1. Several rotaviruses are able to use α4β7 and α4β1 for cell binding or entry, through the recognition of the same α4-subunit domains as natural α4 ligands.

N-terminal targeting of guanine nucleotide exchange factors (GEF) for ADP ribosylation factors (ARF) to the Golgi

2000 ◽  
Vol 113 (11) ◽  
pp. 1883-1889 ◽  
Author(s):  
S.Y. Lee ◽  
B. Pohajdak
Keyword(s):  
Coiled Coil ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Ph Domain ◽  
Adp Ribosylation ◽  
Guanine Nucleotide Exchange ◽  
Coiled Coil Domain ◽  
Nucleotide Exchange Factor ◽  
N Terminus ◽  
Point Mutagenesis

B2-1 (cytohesin-1) is a member of a group of proteins (including ARNO and ARNO3) that are all of similar size and domain composition. The three proteins contain an N-terminal coiled-coil domain, followed by a Sec7 and a pleckstrin homology (PH) domain. While it is well established that the Sec7 domain functions as a guanine nucleotide exchange factor (GEF) for ADP-ribosylation factors (ARFs) and the PH domain anchors the proteins to membrane phosphoinositols, the function of the N-terminal domain is unknown. Here we show that the N terminus of B2-1 (residues 1–54) is necessary and sufficient to target the protein to the Golgi. The Sec7+PH domains of B2-1 (residues 55–398) are not sufficient for Golgi localization. Further deletion analysis and point mutagenesis indicate that the coiled-coil domain within the N terminus is responsible for Golgi targeting. Furthermore, ARNO and ARNO3 N termini also have the same capability of targeting to the Golgi. We conclude that the N-terminal, (α)-helical, coiled-coil domain is used to target this family of proteins to the Golgi complex.

scholarly journals The Fanconi anemia core complex is required for efficient point mutagenesis and Rev1 foci assembly

DNA Repair ◽  
2008 ◽  
Vol 7 (6) ◽  
pp. 902-911 ◽  
Author(s):  
Kanchan D. Mirchandani ◽  
Ryan M. McCaffrey ◽  
Alan D. D’Andrea
Keyword(s):  
Fanconi Anemia ◽  
Core Complex ◽  
Efficient Point ◽  
Point Mutagenesis
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