Recombinant Human MED1 Protein: Usage Protocol & Key Facts

Recombinant Human MED1 Protein is a key mediator subunit used in transcription coactivation studies, requiring careful reconstitution and storage to maintain biological activity.

Product Name

Recombinant Human MED1 Protein

SKU

rp366623

Protein Function

Subunit of the Mediator transcriptional coactivator complex; bridges transcription factors and RNA Pol II

Species Origin

Human (Homo sapiens)

Application

Transcription assays, protein-protein interaction studies, mediator complex reconstitution

Storage Recommendation

Avoid repeated freeze-thaw cycles; aliquot upon first use and store at -80°C for long-term

Background and Biological Significance of MED1

MED1 (Mediator of RNA Polymerase II Transcription Subunit 1), also known as TRAP220, DRIP205, or PBP, is a critical component of the Mediator complex—a multi-subunit transcriptional coactivator that serves as a molecular bridge between gene-specific transcription factors and the general RNA Polymerase II (RNA Pol II) transcription machinery.

MED1 contains two LXXLL nuclear receptor interaction motifs (NR boxes) that enable it to interact directly with ligand-activated nuclear receptors, including PPARγ, ERα, and thyroid hormone receptor, making it an essential coactivator in hormone-responsive gene expression. Dysregulation of MED1 has been implicated in cancer progression, metabolic disorders, and developmental abnormalities, highlighting its importance as a research target.

Recombinant Human MED1 Protein (rp366623) enables researchers to study Mediator complex assembly, transcription factor interactions, and coactivation mechanisms in well-defined biochemical systems.

Reagents, Equipment, and Safety Precautions

Required reagents:

• Recombinant Human MED1 Protein (rp366623, Aladdin Scientific)
• Sterile, ultrapure water or compatible reconstitution buffer (e.g., PBS pH 7.4 with 0.1% BSA as carrier protein, or as specified in the product datasheet)
• Protease inhibitor cocktail (optional, for extended incubation experiments)
• Appropriate assay buffers depending on downstream application (binding buffer, transcription buffer, etc.)

Required equipment:

• Microcentrifuge
• Vortex mixer (use gently)
• Benchtop cooling block or ice bucket
• Aliquotting tubes (low-protein-binding microcentrifuge tubes recommended)
• -80°C freezer for long-term storage

Safety precautions:

• Handle all recombinant proteins on ice or at 4°C to preserve activity.
• Wear standard personal protective equipment (PPE) including gloves and lab coat.
• Dispose of biological materials according to your institutional biosafety guidelines.

Reconstitution and Aliquoting Protocol

Follow these steps to reconstitute and aliquot Recombinant Human MED1 Protein (rp366623) for optimal activity and stability:

1. Equilibrate: Allow the vial to equilibrate to room temperature for 5–10 minutes before opening. Do not heat.
2. Centrifuge: Briefly centrifuge the vial (1,000–2,000 × g, 30 seconds) to bring lyophilized material to the bottom of the tube.
3. Reconstitute: Add the volume of sterile ultrapure water or reconstitution buffer specified in the product datasheet directly to the vial. The recommended diluent and volume should be confirmed from the product-specific datasheet (rp366623). Adding 0.1% BSA to the buffer can help stabilize the protein and reduce non-specific adsorption to tube surfaces.
4. Mix gently: Do not vortex vigorously. Gently pipette up and down or roll the vial between your palms until the protein is fully dissolved. Avoid foaming.
5. Incubate: Allow the reconstituted protein to sit on ice for 5 minutes to ensure complete solubilization.
6. Aliquot: Divide the reconstituted protein into single-use aliquots using low-protein-binding microcentrifuge tubes to avoid repeated freeze-thaw cycles.
7. Store: Use immediately or snap-freeze aliquots in liquid nitrogen and store at -80°C. Avoid storing at -20°C for extended periods.

Note: Specific reconstitution buffer composition, volume, and final protein concentration should always be confirmed in the product-specific datasheet provided by Aladdin Scientific for rp366623.

Experimental Applications and Assay Tips

Recombinant Human MED1 Protein (rp366623) is suitable for a range of biochemical and cell-free applications:

• Protein–protein interaction (PPI) assays: Use MED1 as bait or prey in pull-down or co-immunoprecipitation (co-IP) experiments to map interactions with nuclear receptors or other Mediator subunits.
• In vitro transcription assays: Incorporate MED1 into reconstituted transcription systems to assess its coactivation function with nuclear receptor ligands (e.g., PPARγ agonists).
• ELISA and binding assays: Coat MED1 on plates or use it as a labeled binding partner to quantify interactions with transcription factors.
• Structural and biophysical studies: Use MED1 as a component in SEC, ITC, or SPR experiments to characterize binding affinities and stoichiometries.

Tips for best results:

• Determine the optimal working concentration empirically for each assay format; titrate the protein to avoid activity loss from excess protein.
• Always include a positive control (e.g., known MED1-binding nuclear receptor) and negative controls in interaction studies.
• Pre-clear lysates or buffers to minimize non-specific background in pull-down experiments.
• Confirm protein integrity by SDS-PAGE before critical experiments.

Troubleshooting Guide

Use the following troubleshooting table to address common issues encountered when working with Recombinant Human MED1 Protein:

Problem	Possible Cause	Suggested Solution
Protein does not dissolve completely	Insufficient reconstitution buffer or inadequate mixing	Add additional buffer in small increments; mix by gentle pipetting; allow more time on ice
Low or no activity in assay	Protein degradation due to improper storage or repeated freeze-thaw	Use freshly reconstituted aliquots; confirm storage at -80°C; avoid repeated freeze-thaw cycles
High background in pull-down assay	Non-specific binding to beads or tubes	Add 0.1–0.5% BSA to binding buffer; pre-block beads; use low-protein-binding tubes
Unexpected bands on SDS-PAGE	Protein aggregation or degradation; contaminants	Centrifuge reconstituted solution at 10,000 × g for 5 min before use; add protease inhibitors
Inconsistent results between experiments	Variable protein concentration after reconstitution	Measure protein concentration by BCA or Bradford assay after each reconstitution; normalize across experiments

Frequently asked questions

What is the recommended storage condition for Recombinant Human MED1 Protein (rp366623)?

Recombinant Human MED1 Protein should be stored at -80°C for long-term stability. Upon first use, aliquot the reconstituted protein into single-use volumes using low-protein-binding tubes to avoid repeated freeze-thaw cycles, which can lead to protein degradation and loss of activity.

What applications is Recombinant Human MED1 Protein suitable for?

Recombinant Human MED1 Protein (rp366623) is suitable for protein–protein interaction assays (pull-down, co-IP), in vitro transcription studies, ELISA-based binding assays, and biophysical characterization methods such as SPR and ITC. It is particularly useful for studying MED1 interactions with nuclear receptors and other components of the Mediator complex.

How should I reconstitute Recombinant Human MED1 Protein to maintain its activity?

Reconstitute the protein by adding the volume of sterile ultrapure water or buffer specified in the product datasheet directly to the vial, then mix gently by pipetting—do not vortex. Keep the protein on ice at all times and confirm the exact reconstitution conditions in the rp366623 product-specific datasheet from Aladdin Scientific.

Why is MED1 considered an important target in cancer and metabolic disease research?

MED1 bridges nuclear receptors—including those activated by hormones and metabolic ligands—with the general transcription machinery, making it a master regulator of gene expression programs. Overexpression or dysregulation of MED1 has been associated with breast cancer progression, prostate cancer, and metabolic syndromes linked to PPARγ signaling, making it an attractive target for mechanistic and therapeutic research.

References

1. Malik S, Roeder RG. The metazoan Mediator co-activator complex as an integrative hub for transcriptional regulation. Nature Reviews Genetics. 2010;11(11):761-772. doi:10.1038/nrg2901
2. Ito M, et al. Identity between TRAP and SMCC complexes indicates novel pathways for the function of nuclear receptors and diverse mammalian activators. Molecular Cell. 1999;3(3):361-370.
3. Aladdin Scientific. Recombinant Human MED1 Protein, SKU rp366623. Product Datasheet.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.