1. Since applications vary, each investigator should titrate the reagent to obtain optimal results. 2. Please refer to us for technical protocols. 3. Caution: Sodium azide yields highly toxic hydrazoic acid under acidic conditions. Dilute azide compounds in running water before discarding to avoid accumulation of potentially explosive deposits in plumbing.
Purification
The monoclonal antibody was purified from tissue culture supernatant or ascites by affinity chromatography.
SREBF1
Reactivity: Human
WB, ELISA
Host: Rabbit
Polyclonal
unconjugated
Application Notes
The IgG-2A4 antibody may be used for western blot analysis (0.5 to 1 µg/ml) and immunoprecipitation (2 µg/ml). U-937 human histiocytic lymphoma cells (ATCC CRL-1593) or HeLa human cervical carcinoma cells (ATCC CCL-2) are recommended as positive controls for these applications.
This product contains Sodium azide: a POISONOUS AND HAZARDOUS SUBSTANCE which should be handled by trained staff only.
Storage
4 °C
Storage Comment
Store undiluted at 4°C.
Sakai, Nohturfft, Cheng, Ho, Brown, Goldstein: "Identification of complexes between the COOH-terminal domains of sterol regulatory element-binding proteins (SREBPs) and SREBP cleavage-activating protein." in: The Journal of biological chemistry, Vol. 272, Issue 32, pp. 20213-21, (1997) (PubMed).
Wang, Zelenski, Yang, Sakai, Brown, Goldstein: "Cleavage of sterol regulatory element binding proteins (SREBPs) by CPP32 during apoptosis." in: The EMBO journal, Vol. 15, Issue 5, pp. 1012-20, (1996) (PubMed).
Wang, Pai, Wiedenfeld, Medina, Slaughter, Goldstein, Brown: "Purification of an interleukin-1 beta converting enzyme-related cysteine protease that cleaves sterol regulatory element-binding proteins between the leucine zipper and transmembrane domains." in: The Journal of biological chemistry, Vol. 270, Issue 30, pp. 18044-50, (1995) (PubMed).
Sato, Yang, Wang, Evans, Ho, Goldstein, Brown: "Assignment of the membrane attachment, DNA binding, and transcriptional activation domains of sterol regulatory element-binding protein-1 (SREBP-1)." in: The Journal of biological chemistry, Vol. 269, Issue 25, pp. 17267-73, (1994) (PubMed).
Target
SREBF1
(Sterol Regulatory Element Binding Transcription Factor 1 (SREBF1))
SREBP-1 and -2 (sterol-regulatory element binding proteins-1 and -2) are transcription factors which participate in the control of cholesterol homeostasis. SREBPs proteins, which are attached to the endoplasmic reticulum and nuclear envelope, are proteolytically cleaved and thus activated in response to conditions of low cellular sterol. Upon activation of SREBP-1 or -2, an ~480-500 amino acid, N-terminal cleavage fragment of these proteins enters the nucleus and activates transcription of enzymes and other proteins required for cholesterol synthesis. Proteases which cleave SREBPs have been identified and include SCA (SREBP-cleavage activity), as well as a key regulator of apoptotic pathways, caspase-3. SREBP proteins containing point mutations at caspase-3 cleavage sites (Asp460 in SREBP-1 and Asp468 in SREBP-2) do not become cleaved following induction of apoptosis, suggesting that SREBPs may play some role in apoptotic processes. However, sterol-regulated vs. apoptosis-associated cleavage of SREBP proteins appears to be independantly regulated. On SDS-PAGE, sterol-regulated cleavage fragments of SREBP proteins migrate more slowly (i.e., higher molecular weight) than do staurosporin-induced fragments. In addition, staurosporin-induced SREBP cleavage products may appear as a doublet, with the upper band representing a phosphorylated form of SREBP. On SDS-PAGE, full length, precursor forms of SREBP-1 and -2 migrate at ~125 kDa, while proteolytic cleavage fragments may be observed as a cluster of bands between 60 - 70 kDa. The IgG-2A4 antibody recognizes human and hamster SREBP-1. The antibody recognizes the N-terminal (basic helix-loop-helix) domain of human SREBP-1. A fusion protein containing N-terminal amino acids 301-407 (the bHLH/leucine zipper domain), was used as immunogen. The antibody recognizes both the 125 kDa precursor and 60-70 kDa mature, cleaved forms of SREBP-1.