Recombinant Human GFI1 Protein: Function & Research Uses

Recombinant Human GFI1 Protein is a eukaryotically expressed zinc-finger transcriptional repressor that plays essential roles in hematopoietic stem cell maintenance, lymphoid and myeloid differentiation, and is implicated in multiple hematological malignancies, making it a critical reagent for gene regulation and cancer biology research.

Protein Name

Growth Factor Independence 1 (GFI1)

SKU

rp377563

Protein Type

Recombinant Human Protein

Molecular Function

Zinc-finger transcriptional repressor

Key Research Areas

Hematopoiesis, stem cell biology, oncology, gene regulation

Supplier Reference

absea#PP-11040

What Is GFI1? Biological Background

Growth Factor Independence 1 (GFI1) is a nuclear zinc-finger protein that functions as a sequence-specific transcriptional repressor. The human GFI1 gene encodes a protein containing six C-terminal C2H2-type zinc-finger domains responsible for DNA binding and an N-terminal SNAG (Snail/Gfi) domain that mediates transcriptional repression through recruitment of histone-modifying co-repressor complexes, including LSD1/CoREST.

GFI1 was originally identified as a proto-oncogene activated by retroviral insertion in T-cell lymphomas. Subsequent research established its central role in normal hematopoiesis: GFI1 is expressed in hematopoietic stem cells (HSCs), granulocytes, lymphocytes, and inner ear hair cells. Loss-of-function mutations in GFI1 result in severe congenital neutropenia, demonstrating its non-redundant requirement for granulopoiesis.

Beyond normal development, GFI1 is dysregulated in acute myeloid leukemia (AML), T-cell acute lymphoblastic leukemia (T-ALL), and other hematological malignancies, positioning it as both a transcriptional regulator of interest and a potential therapeutic target.

Protein Structure and Biochemical Properties

GFI1 belongs to the GFI family of zinc-finger proteins, which also includes GFI1B. The defining structural features of GFI1 are:

• SNAG domain (N-terminus): A conserved ~20 amino acid repressor domain shared with the Snail family. It recruits epigenetic co-repressors such as LSD1 (KDM1A) to silence target gene promoters via H3K4 demethylation.
• Intermediate region: Contains a conserved spacer sequence of unclear direct function but important for protein stability and interaction specificity.
• Six C2H2 zinc fingers (C-terminus): Mediate sequence-specific binding to the GFI1 consensus DNA motif (5'-TAAATCAC(A/T)GCA-3'), enabling targeted transcriptional repression.

Recombinant Human GFI1 Protein (rp377563) is produced using recombinant expression technology to ensure consistent batch-to-batch quality suitable for in vitro biochemical assays, protein interaction studies, and antibody validation. Researchers should consult the product datasheet for specific details on tag configuration, purity grade, and recommended storage conditions.

Key Research Applications

Recombinant Human GFI1 Protein is a versatile reagent supporting a wide range of experimental workflows:

1. Transcription factor binding assays: Use purified GFI1 protein in electrophoretic mobility shift assays (EMSA) or fluorescence polarization assays to characterize DNA-binding affinity and specificity at target promoters.
2. Protein–protein interaction studies: GFI1 interacts with co-repressors (LSD1, HDAC1/2, CoREST) and other transcription factors. Pull-down, co-immunoprecipitation (co-IP), and surface plasmon resonance (SPR) experiments benefit from recombinant GFI1 as bait or analyte.
3. Antibody validation and Western blotting standards: Recombinant GFI1 serves as a positive control or molecular weight standard when validating anti-GFI1 antibodies in Western blot, ELISA, and immunofluorescence applications.
4. Structural and biophysical studies: Purified recombinant protein supports circular dichroism (CD) spectroscopy, isothermal titration calorimetry (ITC), and X-ray crystallography or cryo-EM studies aimed at resolving GFI1–DNA or GFI1–co-repressor complex structures.
5. Drug discovery: GFI1 is a candidate target for hematological malignancies. Recombinant protein enables high-throughput screening of small molecules that disrupt GFI1 SNAG–LSD1 interactions or zinc-finger–DNA contacts.

Handling, Storage, and Quality Considerations

To preserve the activity and integrity of Recombinant Human GFI1 Protein, researchers should follow best-practice guidelines for recombinant zinc-finger proteins:

• Storage: Store lyophilized or liquid protein at the temperature specified on the product datasheet (typically −20 °C or −80 °C for long-term storage). Avoid repeated freeze–thaw cycles by preparing single-use aliquots upon first reconstitution.
• Reconstitution: Reconstitute lyophilized protein in the buffer recommended in the datasheet. Allow the vial to equilibrate to room temperature before opening to minimize condensation-related protein aggregation.
• Zinc-finger stability: Zinc-finger domains require intact zinc coordination for proper folding and DNA binding. Avoid chelating agents (EDTA, EGTA) in working buffers unless intentionally removing zinc for denaturation experiments.
• Reducing conditions: Include a mild reducing agent (e.g., 1–5 mM DTT or TCEP) in storage and working buffers to prevent disulfide-mediated aggregation of cysteine residues within the zinc-finger motifs.
• Purity and QC: Lot-specific purity data (SDS-PAGE, HPLC) and activity data are provided on the Certificate of Analysis (CoA). Always verify the CoA before initiating critical experiments.

For specific purity percentage, host expression system, tag information, and endotoxin levels of rp377563, refer to the official Aladdin Scientific product page or contact technical support.

Frequently asked questions

What is the function of GFI1 in hematopoiesis?

GFI1 is a zinc-finger transcriptional repressor essential for hematopoietic stem cell quiescence, granulopoiesis, and lymphopoiesis. It silences target genes by recruiting co-repressor complexes including LSD1 and HDACs. Loss-of-function mutations cause severe congenital neutropenia, underscoring its critical role in normal blood cell development.

What assays is Recombinant Human GFI1 Protein (rp377563) suitable for?

Recombinant Human GFI1 Protein is suitable for EMSA, co-immunoprecipitation, pull-down assays, surface plasmon resonance, Western blot positive controls, ELISA antibody validation, and biophysical studies such as ITC or CD spectroscopy. It is also used in drug-discovery screens targeting GFI1–co-repressor or GFI1–DNA interactions. Refer to the product datasheet for validated applications specific to this lot.

Why should EDTA be avoided when working with GFI1 protein?

GFI1 contains six C2H2 zinc-finger domains that coordinate zinc ions essential for proper protein folding and DNA-binding activity. EDTA and other chelating agents sequester zinc ions, which can cause zinc-finger unfolding and irreversible loss of protein function. Use zinc-free, chelator-free buffers for all GFI1 binding and activity assays.

How is GFI1 related to cancer, and why is it a research target?

GFI1 was originally identified as a proto-oncogene in retroviral T-cell lymphoma models. It is overexpressed or mutated in acute myeloid leukemia (AML), T-cell acute lymphoblastic leukemia, and other hematological cancers. Because GFI1 drives malignant gene-expression programs partly through its SNAG-domain interaction with LSD1, it is actively investigated as a therapeutic target, and recombinant GFI1 protein supports related mechanistic and drug-screening studies.

References

1. Grimes HL, et al. The Gfi-1 proto-oncoprotein contains a novel transcriptional repressor domain, SNAG, and inhibits G1 arrest induced by interleukin-2 withdrawal. Mol Cell Biol. 1996;16(11):6263-6272. PMID:8887654
2. Hock H, et al. Gfi-1 restricts proliferation and preserves functional integrity of haematopoietic stem cells. Nature. 2004;431(7011):1002-1007. PMID:15457180
3. Karsunky H, et al. Inflammatory reactions and severe neutropenia in mice lacking the transcriptional repressor Gfi1. Nat Genet. 2002;30(3):295-300. PMID:11850619
4. Saleque S, et al. Epigenetic regulation of hematopoietic differentiation by Gfi-1 and Gfi-1b is mediated by the cofactors CoREST and LSD1. Mol Cell. 2007;27(4):562-572. PMID:17707228

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