Recombinant Human ASXL1 Protein: Research Guide & Protocol

Recombinant Human ASXL1 Protein is a critical epigenetic regulatory protein involved in chromatin remodeling and histone modification, widely used in studies of myeloid malignancies, polycomb complex biology, and transcriptional silencing mechanisms.

Product Name

Recombinant Human ASXL1 Protein

SKU

rp366905

Protein Function

Epigenetic regulator; component of the Polycomb Repressive Deubiquitinase (PR-DUB) complex; involved in H2A deubiquitination and transcriptional regulation

Species

Human (Homo sapiens)

Application Areas

Epigenetic research, chromatin biology, oncology, biochemical assays, protein-protein interaction studies

Storage Recommendation

Avoid repeated freeze-thaw cycles; store at -80 °C for long-term stability (verify with datasheet)

Format

Recombinant protein; specific formulation details available on product datasheet

Background: ASXL1 Biology and Significance

ASXL1 (Additional Sex Combs Like 1) is a member of the mammalian Enhancer of Trithorax and Polycomb (ETP) protein family, which plays a central role in epigenetic gene regulation. At the molecular level, ASXL1 is an essential scaffold component of the Polycomb Repressive Deubiquitinase (PR-DUB) complex, where it partners with the deubiquitinase BAP1 to catalyze the removal of monoubiquitin from histone H2A at lysine 119 (H2AK119ub1).

ASXL1 functions as a dual regulator of chromatin, participating in both transcriptional activation and repression depending on cellular context. It interacts with a broad range of chromatin-associated proteins, including members of the Polycomb and Trithorax group complexes, nuclear hormone receptors, and transcription factors such as HP1 and members of the Hox gene regulatory network.

From a disease perspective, somatic loss-of-function mutations in ASXL1 are among the most frequently observed lesions in myeloid malignancies, including myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), and acute myeloid leukemia (AML). These mutations are associated with poor prognosis and are thought to disrupt normal hematopoietic stem cell differentiation through deregulation of Polycomb-mediated gene silencing.

Protein Handling, Reconstitution, and Storage Guidelines

Proper handling of Recombinant Human ASXL1 Protein is essential to preserve activity and ensure reproducible experimental results. Researchers should adhere to the following guidelines:

• Upon receipt: Inspect the vial for integrity. Briefly centrifuge to collect all material at the bottom of the vial before opening.
• Reconstitution: Reconstitute the lyophilized protein (if applicable) using the buffer recommended in the product datasheet. Gently mix by pipetting; avoid vortexing to prevent protein denaturation. Allow the reconstituted protein to equilibrate on ice before use.
• Aliquoting: Prepare single-use aliquots immediately after reconstitution to minimize freeze-thaw cycles, which can lead to loss of protein activity and aggregation.
• Short-term storage: Store at 4 °C for up to the period specified on the datasheet if the protein will be used within days.
• Long-term storage: Store at -80 °C. Avoid repeated freeze-thaw cycles. Adding a carrier protein such as BSA (0.1% final concentration) may improve stability during long-term storage, but verify compatibility with your downstream assay.
• Working concentration: Determine the optimal working concentration empirically for each application. Refer to the product datasheet and relevant literature for initial guidance.

Always consult the specific product datasheet for rp366905 for authoritative handling instructions, as formulation details may vary by lot.

Key Research Applications

Recombinant Human ASXL1 Protein is suitable for a range of biochemical and cell-biology applications relevant to epigenetic and oncology research:

• Protein–Protein Interaction Studies: ASXL1 is used to map interactions within the PR-DUB complex (e.g., with BAP1, FOXK1/2, OGT) and with other chromatin regulatory proteins, using techniques such as co-immunoprecipitation (co-IP), pull-down assays, and surface plasmon resonance (SPR).
• Enzymatic / Deubiquitinase Activity Assays: In complex with BAP1, ASXL1 supports H2AK119 deubiquitination. Reconstitution of the PR-DUB complex in vitro enables biochemical characterization of its catalytic activity and inhibitor screening.
• Structural Biology: Recombinant ASXL1 fragments or domains are used for X-ray crystallography, cryo-EM, and NMR studies to elucidate structural determinants of complex assembly and substrate recognition.
• Western Blot / ELISA Standards: Recombinant protein can serve as a positive control or standard in immunoassays designed to detect or quantify ASXL1.
• Drug Discovery and Inhibitor Screening: Given the pathological relevance of ASXL1 mutations in myeloid cancers, the protein is a tool for screening small-molecule modulators targeting the PR-DUB complex.
• In Vitro Transcription/Translation and Functional Studies: Used to investigate the mechanistic basis of ASXL1-driven transcriptional regulation in defined biochemical systems.

Quality Considerations and Experimental Best Practices

To obtain reliable and reproducible data with Recombinant Human ASXL1 Protein, researchers should consider the following quality and experimental best practices:

• Purity verification: Confirm protein purity by SDS-PAGE prior to critical experiments. The expected molecular weight should be verified against the datasheet, as recombinant constructs may include affinity tags (e.g., His-tag, GST) that shift the apparent molecular weight.
• Activity validation: Where possible, validate biological activity using a relevant functional assay (e.g., deubiquitinase activity assay in the context of the PR-DUB complex) prior to use in higher-throughput screening.
• Endotoxin levels: For cell-based assays, confirm that endotoxin levels in the protein preparation are within acceptable limits, as endotoxin contamination can confound cellular responses.
• Lot-to-lot consistency: When transitioning between protein lots, run parallel experiments with both old and new lots to confirm consistency of activity and binding.
• Carrier protein compatibility: If BSA or other carriers are added for stabilization, confirm they do not interfere with downstream assays, particularly binding or enzymatic assays.
• Controls: Always include appropriate positive and negative controls, including denatured or heat-inactivated ASXL1, in functional assays to validate assay performance.

Frequently asked questions

What is the biological function of ASXL1 protein?

ASXL1 (Additional Sex Combs Like 1) is an epigenetic regulator that acts as a scaffold component of the Polycomb Repressive Deubiquitinase (PR-DUB) complex, partnering with BAP1 to remove monoubiquitin from histone H2A at lysine 119. It plays dual roles in transcriptional activation and repression and is critical for hematopoietic stem cell homeostasis.

Why is ASXL1 important in cancer research?

Somatic loss-of-function mutations in ASXL1 are among the most frequently identified lesions in myeloid malignancies, including myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), and acute myeloid leukemia (AML). These mutations disrupt Polycomb-mediated gene silencing, impair normal hematopoietic differentiation, and are associated with poor clinical prognosis, making ASXL1 an important target for oncology research and drug discovery.

How should Recombinant Human ASXL1 Protein (rp366905) be stored to maintain activity?

For long-term storage, Recombinant Human ASXL1 Protein should be kept at -80 °C and protected from repeated freeze-thaw cycles by preparing single-use aliquots upon reconstitution. For short-term use, storage at 4 °C is acceptable for the period specified on the product datasheet. Always consult the specific datasheet for rp366905 for authoritative storage conditions and shelf-life information.

What are the recommended applications for Recombinant Human ASXL1 Protein?

Recombinant Human ASXL1 Protein is suitable for protein-protein interaction studies (co-IP, pull-down), in vitro deubiquitinase activity assays in the context of the PR-DUB complex, structural biology (crystallography, cryo-EM), use as a western blot or ELISA standard, and small-molecule inhibitor screening relevant to myeloid malignancy research. Optimal assay conditions should be determined empirically and guided by the product datasheet.

Does ASXL1 have an intrinsic enzymatic activity?

ASXL1 itself does not possess intrinsic enzymatic activity; rather, it acts as a scaffold that recruits and activates the deubiquitinase BAP1 within the PR-DUB complex. The catalytic activity (H2AK119 deubiquitination) resides in BAP1, but ASXL1 is essential for full complex activity and substrate targeting. Reconstitution of both proteins is typically required for in vitro enzymatic assays.

References

1. Asada S, Goyama S, Inoue D, et al. Mutant ASXL1 cooperates with BAP1 to promote myeloid leukaemogenesis. Nature Communications. 2018.
2. Scheuermann JC, de Ayala Alonso AG, Oktaba K, et al. Histone H2A deubiquitinase activity of the Polycomb Repressive Complex PR-DUB. Nature. 2010.
3. Gelsi-Boyer V, Trouplin V, Adelaide J, et al. Mutations of polycomb-associated gene ASXL1 in myelodysplastic syndromes and chronic myelomonocytic leukaemia. British Journal of Haematology. 2009.
4. Abdel-Wahab O, Mullally A, Hedvat C, et al. Genetic characterization of TET2 mutations in myeloid malignancies. Blood. 2009. [Cited for context on myeloid mutation landscape.]

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