Catalog # SX1625

unphosphorylated SK1 (Ser-225) Peptide

Blocking Peptide

Application / Dilution
ELISA50 ng/well

Size 50 μg



Sphingolipids are metabolized into bioactive products that include ceramide, sphingosine, and sphingosine-1-phosphate (S1P). Sphingosine Kinase (SK) catalyzes the phosphorylation of the lipid sphingosine, creating S1P. S1P subsequently signals through cell surface G protein-coupled receptors, as well as intracellularly, to modulate cell proliferation, survival, motility and differentiation. Two isoforms of SK have been identified, SK1 and SK2. The mRNA for both of these isoforms is widely expressed with SK1 expression highest in brain, heart, kidney, thymus, spleen and lung, while SK2 is highest in kidney and liver. SKs can be activated through growth factor, G protein-coupled, and immunoglobulin receptor signalling. SK1 has been shown to mediate cell growth, prevention of apoptosis, and cellular transformation, and is upregulated in a variety of human tumors. Regulation of SK1 may occur through ERK mediated phosphorylation of Ser-225. This phosphorylation leads to increased activity and translocation to the plasma membrane.


Pitson, S.M. et al. (2005) J Exp. Med. 201(1) :49.
Pitson, S.M. et al. (2003) EMBOJ. 22(20) :5491.
Melendez, A.J. et al. (2000) Gene 251(1) :19.

Western blot image of recombinant his-tagged human SK1 protein that was phosphorylated with ERK-2. The Blots were probed with anti-SK1 (Central Region) (SP1621; lanes 1-3) and anti-SK1 (Ser-225) (SP1641; lanes 4-6). Both antibodies where used in the presence of no peptide (lanes 1 & 4), phospho-SK1 (Ser-225) peptide (SX1645; lanes 2 & 5), or unphosphorylated SK1 (Ser-225) peptide (SX1625; lanes 3 & 6).

Unphosphorylated SK1 (Ser-225) synthetic peptide corresponds to amino acids surrounding serine 225 in the central region of human SK1. The sequence has 4 amino acid differences from mouse and 5 from rat SK1, and is not homologous to sequences in SK2.

*For more information, see UniProt Accession Q9NYA1
Blocking Peptide is supplied in 50µl phosphate-buffered saline and 0.05% sodium azide. Store at –20°C. Stable for 1 year.

The products are are safely shipped at ambient temperature for both domestic and international shipments. Each product is guaranteed to match the specifications as indicated on the corresponding technical data sheet. Please store at -20C upon arrival for long term storage.

The peptide is specifically recognized by anti-SK1 (Central region) antibody (SP1621) in ELISA, and has been shown to block the reactivity of SP1621 during Western blot. In addition, the peptide is recommended for use in blocking SP1621 reactivity in immunocytochemistry.

*All molecular weights (MW) are confirmed by comparison to Bio-Rad Rainbow Markers and to western blot mobilities of known proteins with similar MW.

This kit contains: