Cell Signaling Technology

Product Pathways - Cytoskeletal Signaling

OSR1 Antibody #3729

Applications Reactivity Sensitivity MW (kDa) Source
W IF-IC F H Mk B Endogenous 60 Rabbit

Applications Key:  W=Western Blotting  IF-IC=Immunofluorescence (Immunocytochemistry)  F=Flow Cytometry
Reactivity Key:  H=Human  Mk=Monkey  B=Bovine
Species cross-reactivity is determined by Western blot.

Protocols

Specificity / Sensitivity

OSR1 Antibody detects endogenous levels of total OSR1 protein. This antibody does not cross-react with SPAK or other members of the GCK family.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues at the amino terminus of human OSR1. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from 293, HeLa, Jurkat and COS cells using OSR1 Antibody.

Flow Cytometry

Flow Cytometry

Flow cytometric analysis of HeLa cells using OSR1 Antibody (blue) compared to a nonspecific negative control antibody (red).

IF-IC

IF-IC

Confocal immunofluorescent analysis of HeLa cells using OSR1 Antibody (green). Actin filaments have been labeled with Alexa Fluor® 555 phalloidin (red). Blue pseudocolor = DRAQ5™ (fluorescent DNA dye).


Background

SPAK (STE20/SPS1-related Pro/Ala-rich kinase) and OSR1 (oxidative stress responsive 1) are members of the GCK family serine/threonine kinases. Overexpression and in vitro studies demonstrate that SPAK is able to activate p38 MAP kinase indicating a possible role for SPAK in the stress response (1). Yeast two-hybrid screening revealed that SPAK and OSR1 bind to Na-K-2Cl cotransporters NKCC1 and NKCC2 and K-Cl cotransporter KCC3 (2). WNK1 and WNK4 phosphorylate SPAK at Thr243/247 and Ser380 (3-5). Similarly, WNK1 and WNK4 phosphorylate OSR1 at Thr185 and Ser315 (3, 4). Phosphorylation at these sites stimulates SPAK and OSR1 activity, leading to NKCC1 phosphorylation and enhanced NKCC1 activity (3-5). SPAK is also phosphorylated at Ser311 by PKCθ in response to T cell activation. Substitution of Ser311 with Ala or specific siRNA knock-down of SPAK dramatically reduces TCR/CD28-induced AP-1 activation, suggesting SPAK is involved in T cell signaling as well (6).

  1. Johnston, A.M. et al. (2000) Oncogene 19, 4290-4297.
  2. Piechotta, K. et al. (2002) J. Biol. Chem. 277, 50812-50819.
  3. Vitari, A.C. et al. (2005) Biochem. J. 391, 17-24.
  4. Moriguchi, T. et al. (2005) J. Biol. Chem. 280, 42685-42693.
  5. Gagnon, K.B. et al. (2006) Mol. Cell. Biol. 26, 689-698.
  6. Li, Y. et al. (2004) EMBO J. 23, 1112-1122.

Application References

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Companion Products

This product is intended for research purposes only. The product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

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