A1/Bfl-1 Antibody [N2F22] Datasheet

Biological Description

Specificity	A1/Bfl-1 Antibody [N2F22] detects endogenous levels of total A1/Bfl-1 protein.
Background	A1/Bfl-1 (BCL2A1) represents an anti-apoptotic member of the Bcl-2 protein family originally identified as a granulocyte-macrophage colony-stimulating factor (GM-CSF)-inducible gene in mouse bone marrow, exhibiting predominant expression in hematopoietic cells, including neutrophils, macrophages, T lymphocytes, and B lymphocytes, with limited detection in non-hematopoietic tissues such as lung and vascular endothelium. A1/Bfl-1 contains four Bcl-2 homology (BH) domains organized into eight alpha-helices, with helices α4, α5, and α6 corresponding to BH3, BH1, and BH2 domains forming a hydrophobic groove on the protein surface for interaction with pro-apoptotic Bcl-2 family members, although A1 uniquely possesses an acidic glutamate residue at position 78 within this binding groove distinguishing its interaction specificity from other anti-apoptotic relatives. The protein diverges structurally from Bcl-2, Bcl-xL, Bcl-w, and Mcl-1 through its hydrophilic C-terminal domain that lacks a transmembrane anchor, instead containing ubiquitination sites directing rapid proteasomal degradation conferring a short half-life of approximately thirty minutes, comparable to Mcl-1 but contrasting with Bcl-2's twenty-four-hour stability. A1/Bfl-1 expression becomes rapidly induced through NF-κB transcriptional activation in response to diverse inflammatory stimuli, including TNF-α, IL-1β, CD40 ligation, phorbol esters, lipopolysaccharide, and pre-T-cell receptor signaling operating through PLCγ/PKC/NF-κB pathways, positioning A1 as an immediate-early survival response gene. The protein functions by binding and neutralizing BH3-only pro-apoptotic proteins, including Bid, Bim, and Puma with high affinity while exhibiting no detectable binding to Bad, thereby preventing these death activators from triggering Bax/Bak oligomerization and mitochondrial outer membrane permeabilization that would otherwise release cytochrome c and initiate caspase-dependent apoptosis. A1/Bfl-1 displays preferential interaction with Bak over Bax through direct binding that antagonizes Bak-mediated cell death, although conflicting reports describe species-specific differences wherein mouse A1 localizes predominantly to the cytosol requiring interaction partners to impose its site of anti-apoptotic action while human A1/Bfl-1 preferentially targets mitochondria directly. The protein executes critical survival functions during lymphocyte development—A1 expression peaks at the DN3 to DN4 thymocyte transition where pre-TCR signaling-dependent A1 induction proves necessary and sufficient for beta-selection progression, reappears in CD4+ single-positive thymocytes at thirty-fold higher levels than double-positive cells, and becomes strongly upregulated upon T-cell receptor engagement in peripheral T cells along with Noxa to enable survival of high-affinity TCR-bearing antigen-specific clones. A1/Bfl-1 regulates mature follicular B-cell survival downstream of B-cell receptor and PLCγ2 signaling through NF-κB activation, rendering follicular B cells resistant to BCR-induced apoptosis that eliminates transitional B cells during negative selection, with elevated A1 expression documented in systemic lupus erythematosus patients' B cells reflecting dysregulated tolerance mechanisms. The protein mediates neutrophil survival extension during bacterial infection and inflammatory responses by countering spontaneous apoptosis in response to G-CSF, GM-CSF, TNF-α, IFN-γ, IL-8, and lipopolysaccharide stimulation through NF-κB-dependent transcription, with loss of A1-a isoform abolishing LPS-mediated neutrophil survival enhancement although steady-state and inflammatory granulocyte numbers remain normal due to compensatory progenitor activity. A1/Bfl-1 promotes macrophage survival during infection with Mycobacterium bovis BCG, Toxoplasma gondii, and Mycobacterium tuberculosis through NF-κB pathway activation peaking within eight to sixteen hours post-infection, yet paradoxically inhibits autophagosome maturation and acidification in virulent M. tuberculosis-infected macrophages, enabling intracellular bacterial persistence by blocking both autophagy-mediated killing and host cell apoptosis. A1 exhibits functional redundancy with Mcl-1 in mast cell survival, collectively mediating allergic reaction severity by sustaining the survival of tissue-resident mast cells containing histamine-rich inflammatory granules. Calpain proteolytically cleaves A1/Bfl-1 within the N-terminal region, generating pro-apoptotic C-terminal fragments that promote mitochondrial cytochrome c release and apoptosis reversal, representing a potential therapeutic mechanism, although physiological contexts triggering this conversion remain incompletely defined. A1/Bfl-1 overexpression fails to induce lymphoma in transgenic mice, unlike Bcl-2, yet ubiquitination-resistant A1 mutants predispose to lymphomagenesis when co-expressed with dominant-negative p53 and accelerate Myc-induced lymphoma development, while elevated A1 expression in B chronic lymphocytic leukemia, acute myeloid leukemia, and acute promyelocytic leukemia strongly correlates with chemoresistance and poor prognosis.

Specificity

A1/Bfl-1 Antibody [N2F22] detects endogenous levels of total A1/Bfl-1 protein.

Background

A1/Bfl-1 (BCL2A1) represents an anti-apoptotic member of the Bcl-2 protein family originally identified as a granulocyte-macrophage colony-stimulating factor (GM-CSF)-inducible gene in mouse bone marrow, exhibiting predominant expression in hematopoietic cells, including neutrophils, macrophages, T lymphocytes, and B lymphocytes, with limited detection in non-hematopoietic tissues such as lung and vascular endothelium. A1/Bfl-1 contains four Bcl-2 homology (BH) domains organized into eight alpha-helices, with helices α4, α5, and α6 corresponding to BH3, BH1, and BH2 domains forming a hydrophobic groove on the protein surface for interaction with pro-apoptotic Bcl-2 family members, although A1 uniquely possesses an acidic glutamate residue at position 78 within this binding groove distinguishing its interaction specificity from other anti-apoptotic relatives. The protein diverges structurally from Bcl-2, Bcl-xL, Bcl-w, and Mcl-1 through its hydrophilic C-terminal domain that lacks a transmembrane anchor, instead containing ubiquitination sites directing rapid proteasomal degradation conferring a short half-life of approximately thirty minutes, comparable to Mcl-1 but contrasting with Bcl-2's twenty-four-hour stability. A1/Bfl-1 expression becomes rapidly induced through NF-κB transcriptional activation in response to diverse inflammatory stimuli, including TNF-α, IL-1β, CD40 ligation, phorbol esters, lipopolysaccharide, and pre-T-cell receptor signaling operating through PLCγ/PKC/NF-κB pathways, positioning A1 as an immediate-early survival response gene. The protein functions by binding and neutralizing BH3-only pro-apoptotic proteins, including Bid, Bim, and Puma with high affinity while exhibiting no detectable binding to Bad, thereby preventing these death activators from triggering Bax/Bak oligomerization and mitochondrial outer membrane permeabilization that would otherwise release cytochrome c and initiate caspase-dependent apoptosis. A1/Bfl-1 displays preferential interaction with Bak over Bax through direct binding that antagonizes Bak-mediated cell death, although conflicting reports describe species-specific differences wherein mouse A1 localizes predominantly to the cytosol requiring interaction partners to impose its site of anti-apoptotic action while human A1/Bfl-1 preferentially targets mitochondria directly. The protein executes critical survival functions during lymphocyte development—A1 expression peaks at the DN3 to DN4 thymocyte transition where pre-TCR signaling-dependent A1 induction proves necessary and sufficient for beta-selection progression, reappears in CD4+ single-positive thymocytes at thirty-fold higher levels than double-positive cells, and becomes strongly upregulated upon T-cell receptor engagement in peripheral T cells along with Noxa to enable survival of high-affinity TCR-bearing antigen-specific clones. A1/Bfl-1 regulates mature follicular B-cell survival downstream of B-cell receptor and PLCγ2 signaling through NF-κB activation, rendering follicular B cells resistant to BCR-induced apoptosis that eliminates transitional B cells during negative selection, with elevated A1 expression documented in systemic lupus erythematosus patients' B cells reflecting dysregulated tolerance mechanisms. The protein mediates neutrophil survival extension during bacterial infection and inflammatory responses by countering spontaneous apoptosis in response to G-CSF, GM-CSF, TNF-α, IFN-γ, IL-8, and lipopolysaccharide stimulation through NF-κB-dependent transcription, with loss of A1-a isoform abolishing LPS-mediated neutrophil survival enhancement although steady-state and inflammatory granulocyte numbers remain normal due to compensatory progenitor activity. A1/Bfl-1 promotes macrophage survival during infection with Mycobacterium bovis BCG, Toxoplasma gondii, and Mycobacterium tuberculosis through NF-κB pathway activation peaking within eight to sixteen hours post-infection, yet paradoxically inhibits autophagosome maturation and acidification in virulent M. tuberculosis-infected macrophages, enabling intracellular bacterial persistence by blocking both autophagy-mediated killing and host cell apoptosis. A1 exhibits functional redundancy with Mcl-1 in mast cell survival, collectively mediating allergic reaction severity by sustaining the survival of tissue-resident mast cells containing histamine-rich inflammatory granules. Calpain proteolytically cleaves A1/Bfl-1 within the N-terminal region, generating pro-apoptotic C-terminal fragments that promote mitochondrial cytochrome c release and apoptosis reversal, representing a potential therapeutic mechanism, although physiological contexts triggering this conversion remain incompletely defined. A1/Bfl-1 overexpression fails to induce lymphoma in transgenic mice, unlike Bcl-2, yet ubiquitination-resistant A1 mutants predispose to lymphomagenesis when co-expressed with dominant-negative p53 and accelerate Myc-induced lymphoma development, while elevated A1 expression in B chronic lymphocytic leukemia, acute myeloid leukemia, and acute promyelocytic leukemia strongly correlates with chemoresistance and poor prognosis.

Usage Information

Application

WB, IP

Dilution

WB	IP
1:1000	1:100

Reactivity

Human

Source

Rabbit Monoclonal Antibody

MW

18 kDa

Storage Buffer

PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3

Storage
(from the date of receipt)

-20°C (avoid freeze-thaw cycles), 2 years

References

https://pubmed.ncbi.nlm.nih.gov/26890142/
https://pubmed.ncbi.nlm.nih.gov/22342458/

A1/Bfl-1 Antibody [N2F22]

Biological Description

Usage Information

References

Application Data