• Purity

  >95%, by SDS-PAGE with silver staining.

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured in a cell proliferation assay using RT4?D6P2T rat schwannoma cells. The ED    ₅₀ for this effect is 0.2-1.0 μg/mL.

• Source

  E. coli-derived Glu27-Gly175, with an N-terminal Met

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Predicted Molecular Mass

  17 kDa

• SDS-PAGE

  16 kDa, reducing conditions

Data Images

Background: Reg3B

Rat Reg3B (Islets of Langerhans regenerating protein 3), also known as Reg-III alpha, Lithostathine 3, pancreatitis associated protein 2 and Lithostatine 3 is a member of the Reg family of secreted C-type lectin domain-containing pancreatic proteins (1, 2). Reg3B has been categorized in the type 3 subclass of the Reg gene family (3). The rat Reg3B cDNA encodes 174 amino acids (aa) including the 25 aa signal sequence and the 149 aa secreted mature protein. Rat Reg3B shares approximately 83% aa sequence identity with mouse Reg3B and 55% with humans Reg3B (1, 2). Reg proteins are thought to be stress response proteins that stimulate proliferation, particularly in  beta  cells of pancreatic islets (1). Reg3B is expressed primarily by acinar cells in the normal exocrine pancreas, and is up-regulated in NOD (non-obese diabetic) islets, hyperplastic islets, regenerating islets or in response to pancreatic injury or pancreatitis (1-6). IFN-beta causes Reg3B up-regulation in early-onset diabetic NOD mice or in a NOD insulinoma cell line (5). Reg3B is also up-regulated in mice lacking the pancreas-expressed keratin K8, and is thought to be regulated by keratin filament organization (4). It is proposed to serve as an autoantigen in NOD mouse immune-mediated type I diabetes models (5).

• References:

1. Liu, J.-L. et al. (2008) Endocrine Metab. Immune Disord. Drug Targets 8:1.

2. Unno, M. et al. (1993) J. Biol. Chem. 268:15974.

3. Tebar LA. et al. (2008) PNAS. 105:11400.

4. Zhong, B. et al. (2007) Mol. Biol. Cell 18:4969.

5. Gurr, W. et al. (2007) Diabetes 56:34.

6. Lu, Y. et al. (2006) Am. J. Physiol. Endocrinol. Metab. 291:E50.

7. Baeza, N. et al. (1997) FEBS Lett. 416:364.

8. Planas, R. et al. (2006) Diabetologia 49:2379.

• Long Name:

  Regenerating Islet-derived IIIb

• Entrez Gene IDs:

  18489 (Mouse); 24618 (Rat)

• Alternate Names:

  PAP1; Reg3B