Sos-inducible Protein
Sos-inducible Protein - Related Videos
08:46
Green Fluorescent Protein-based Expression Screening of Membrane Proteins in Escherichia coli
0 Views •
Cited by 34 •
2015
A streamlined approach to screening for the expression of recombinant membrane proteins in Escherichia coli based on fusion to green fluorescent protein is presented.
02:43
Transfection of an Inducible Gene Expression System into Cells Expressing a Bacterial Effector Protein
0 Views •
2025
Source: Berens, C. et al. Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling. J. Vis. Exp. (2015)This video demonstrates the use of an inducible expression system to identify where the bacterial effector protein CaeB disrupts the host apoptotic cascade. It outlines the steps for transfecting CaeB-expressing cells with a tetracycline-responsive system to induce pro-apoptotic gene expression in order to identify the point of...
09:52
Electricity-Free, Sequential Nucleic Acid and Protein Isolation
0 Views •
Cited by 4 •
2012
A tool and chemistries are described to sequentially isolate nucleic acids followed by proteins from a sample without the need for electricity. The tool consists of a sorbent held within a transfer pipette while the isolation chemistries are based on solid-phase extraction principles. The isolated macromolecules can be analyzed by immuno-based and PCR-based assays.
08:40
Photo-Induced Cross-Linking of Unmodified Proteins (PICUP) Applied to Amyloidogenic Peptides
0 Views •
Cited by 91 •
2009
Photo-induced cross-linking of unmodified proteins (PICUP) allows characterization of oligomer size distribution in metastable protein mixtures. We demonstrate application of PICUP to three representative amyloidogenic peptides the 40- and 42-residue forms of amyloid β-protein, and calcitonin, and a control peptide growth-hormone releasing factor.
08:52
Chemical Dimerization-Induced Protein Condensates on Telomeres
0 Views •
Cited by 10 •
2021
This protocol illustrates a chemically induced protein dimerization system to create condensates on chromatin. The formation of promyelocytic leukemia (PML) nuclear body on telomeres with chemical dimerizers is demonstrated. Droplet growth, dissolution, localization and composition are monitored with live cell imaging, immunofluorescence (IF) and fluorescence in situ hybridization (FISH).
FAQs
DNA damage or replication stress can leave exposed single-stranded DNA, which promotes RecA activation. Activated RecA then stimulates self-cleavage of the LexA repressor. Once LexA repression is relieved, SOS genes are transcribed, increasing production of proteins involved in DNA repair, recombination, replication, and cell-cycle control.
Exposed single-stranded DNA acts as a signal that DNA replication or genome maintenance is under stress. Its presence promotes RecA activation, linking the physical state of damaged DNA to LexA repressor cleavage and SOS-gene transcription. This connection allows bacterial cells to adjust protein production when ordinary replication cannot proceed normally.
Some SOS-induced proteins help repair lesions or allow replication to continue across damaged DNA templates, increasing the chance that a stressed cell survives. However, damage bypass and related emergency responses can reduce replication accuracy, so survival may occur with more mutations. This tradeoff connects SOS activation with bacterial adaptation and mutagenesis.
Their effects extend beyond direct lesion repair. SOS genes encode proteins associated with repair, genetic recombination, replication across damaged templates, and cell-cycle control. Together, these functions help coordinate genome maintenance with continued growth decisions, allowing the cell to respond to damage while limiting the immediate consequences of replication stress.
A basic investigation compares bacterial protein production under ordinary conditions with production after DNA damage or replication stress. Researchers can then relate increased production to activation of the RecA-LexA regulatory pathway and examine whether the response is associated with repair, recombination, replication support, or cell-cycle control.
These proteins provide a framework for studying how bacteria adapt to DNA damage and replication stress. Their connection to repair, mutagenesis, and genome maintenance makes the SOS response relevant to antimicrobial-resistance research. It also informs antibacterial drug development by identifying stress-response processes that influence bacterial survival after genome damage.