Product Name:
OSBP-pS240
Product Number:
ab-pn844
Target Full Name: Oxysterol-binding protein 1
Target Alias: OSB1; OSBP1; oxysterol binding protein
Product Type Specific: OSBP phosphosite-specific antibody
Antibody Code: PN844
Antibody Target Type: Phosphosite-specific
Antibody Phosphosite: S240
Protein UniProt: P22059
Protein SigNET: OSBP
Antibody Type: Polyclonal
Antibody Host Species: Rabbit
Antibody Immunogen Source: Synthetic phosphopeptide patterned after human OSBP
Antibody Immunogen Sequence: RSL(pS)ELESC
Antibody Immunogen Description: Corresponds to amino acid residues R237 to S244. OSBP S240 phosphorylation is inhibitory to its activity. This is the major in vivo phosphorylation site in OSBP by mass spectrometry (≥60 reports recorded in PhosphoSitePlus). OSBP is known to be phosphorylated at this site in vitro by PKD1 (PRKCM, PRKD1).
Production Method: The immunizing peptide was produced by solid phase synthesis on a multipep peptide synthesizer and purified by reverse-phase hplc chromatography. Purity was assessed by analytical hplc and the amino acid sequence confirmed by mass spectrometry analysis. This peptide was coupled to KLH prior to immunization into rabbits. New Zealand White rabbits were subcutaneously injected with KLH-coupled immunizing peptide every 4 weeks for 4 months. The sera from these animals was applied onto an agarose column to which the immunogen peptide was thio-linked. Antibody was eluted from the column with 0.1 M glycine, pH 2.5. Subsequently, the antibody solution was neutralized to pH 7.0 with saturated Tris.
Antibody Modification: Unconjugated. Contact KInexus if you are interest in having the antibody biotinylated or coupled with fluorescent dyes.
Antibody Concentration: 1 mg/ml
Storage Buffer: Phosphate buffered saline pH 7.4, 0.05% Thimerasol
Storage Conditions: For long term storage, keep frozen at -40°C or lower. Stock solution can be kept at +4°C for more than 3 months. Avoid repeated freeze-thaw cycles.
Product Use: Western blotting | Antibody microarray
Antibody Dilution Recommended: 2 µg/ml for immunoblotting
Antibody Species Reactivity: This antibody detects the target phosphoprotein in the following species due to conservation of amino acid sequence: Human | Chimpanzee | Rhesus macaque | Dog | Rat | Mouse |Chicken.
Related Product 1: OSBP S379+S382 phosphorylation antibody (Cat. No.: AB-PN1006)
Scientific Background: OSBP (Oxysterol-binding protein) is a widely distrubuted, highly conserved cytoplasmic lipid-transfer protein that regulates cellular cholesterol homeostasis by transporting cholesterol from the ER to the Golgi. It regulates cholesterol efflux by decreasing ABCA1 stability. OSBP has a hydrophobic pocket that binds a single sterol (cholesterol or 25-hydroxycholesterol) and a C-terminal OSBP-related domain (ORD). It acts as a bridge, anchoring to the endoplasmic reticulum (ER) via a FFAT motif and to the Golgi apparatus via a PH domain. It operates a "counter-current" transport mechanism, transferring cholesterol to the Golgi while transporting phosphoinositide PI4P in the opposite direction. The PI4P is degraded by the SAC1/SACM1L phosphatase in the endoplasmic reticulum. OSBP acts as a scaffold at membrane contact sites to regulate lipid metabolism, signaling pathways (e.g., ERK1/2), and vesicle trafficking. Upon cholesterol binding, OSBP scaffolds phosphatases (PP2A and HePTP) which inhibit ERK1/2 signaling, whereas 25-hydroxycholesterol causes their disassembly. It is exploited by viruses for replication and is linked to cancer cell proliferation and signaling. This description may include information annotated by UniProt and/or Google AI.