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Transcription Factors
Signaling pathways transduce extracellular signals to affect transcription factor (TF) mediated gene regulation. TFs are sequence-specific DNA-binding proteins that control the transcription of DNA to mRNA. Approximately, 10% of genes in the human genome encode TFs, which makes them the single largest family of human proteins.
The function of TFs is to regulate (turn on and off) gene transcription according to cellular signaling to make sure the right genes are expressed in the right amount on the right occasion. TFs work alone or with other proteins/cofactors to regulate a diversity of cellular processes, such as cell division, cell growth, metabolism, stress response and apoptosis. Mutations in TFs cause certain diseases. Thus, they are potential drug targets.
The key to understanding the mechanism of a signaling pathway is to identify and characterize the TFs functioning downstream the signaling pathway. CD BioSciences offers a complete portfolio of solutions covering every aspect of TF studies, including binding motif analysis, domain mapping, and interacting protein identification.
Introduction of TFs
Definition
Transcription factors (TFs) are proteins binding to DNA, and promoting (as transcription activators) or blocking (as transcription repressors) the recruitment of RNA polymerases to perform the transcription of genes.
Structure
DNA-binding Domain (DBD) binds DNA, such as basic helix-loop-helix (bHLH) and basic-leucine zipper (bZIP). DNA sequences that TFs bind to are often referred to as transcription factor-binding sites or response elements.
Activation Domain (AD) interacts with other proteins (transcription coregulators) to stimulate transcription.
Some TFs, such as nuclear hormone receptors (NHRs), possess a Signal-sensing Domain (SSD) which directly senses signals. Many TFs also contain Nuclear Localization Signal/Sequence (NLS), by which they are directed to the nucleus.
Regulation
The most important role of TFs is to regulate the number of gene products (i.e., RNAs and proteins) available to the cells, meanwhile, TFs themselves are also under multiple layers of regulation and control. Their expression, localization, activation, accessibility of DNA and interaction with other cofactors are all well controlled by signaling pathways.
Classification
TFs can be classified by their mechanism of action, regulatory function, or sequence homology in their DNA-binding domains, among which the third one is commonly used. The followings are some examples.
| Superclass | Class | Family |
| Basic Domains | Leucine zipper factors (bZIP) | AP-1(-like) components (e.g., c-Fos/c-Jun) |
| CREB | ||
| C/EBP-like factors | ||
| Helix-loop-helix factors (bHLH) | Myogenic transcription factors (MyoD) | |
| Helix-loop-helix / leucine zipper factors (bHLH-ZIP) | c-Myc | |
| Zinc-coordinating DNA-binding domains | Cys4 zinc finger of nuclear receptor type | Steroid hormone receptors |
| Helix-turn-helix | Fork head / winged helix | FOX |
| Heat Shock Factors | HSF | |
| beta-Scaffold Factors with Minor Groove Contacts | STAT | STAT |
| p53 | p53 |
Solutions for TFs
Our solutions include but are not limited to the following.
TFs Identification
- Identifying TFs functioning downstream of your signaling pathways of interest.
TF-DNA Interaction Analysis
- Performing ChIP-seq to analyze TF-DNA interaction and identify response element/binding motif of TFs.
Gene Expression Profiling
- Genome-widely analyzing genes transcriptions to determine which genes are transcriptionally up-/down-regulated by certain TFs.
Domain Mapping
- Determining the nuclear localization signal/sequence (NLS), DNA binding domain (DBD), activation domain (AD), and signal-sensing domain (SSD) of TFs.
Structure Analysis
- Analyzing the structures of TFs.
Nuclear Localization
- Determining the nuclear localization of TFs.
- Detecting translocation events of TFs if any.
Activation Analysis
- Determining how TFs are activated or deactivated, for example, by ligand binding, phosphorylation, or dimerization (homo- or hetero-).
Interacting Protein Identification
- Identifying interaction proteins of TFs, such as kinases, phosphatases, and transcription coregulators.
Ligand Identification
- Identifying ligands bind to NHRs (a special group of TFs).
- Screening for inhibitors/activators for NHRs.
Features
CD BioSciences offers cost-effect, high quality and hassle-free transcription factor related solutions to our clients worldwide. We guarantee to deliver our products and results on time. Please feel free to contact us.
For research use only. Not intended for any clinical use.