GM-CSF R alpha Protein, Human (HEK293, His)

GM-CSF R alpha is the alpha subunit of the heterodimeric receptor for colony stimulating factor 2. GM-CSF R alpha binds to the cytokine with high specificity and low affinity^[1]. GM-CSF R alpha binds to GM-CSF and induces cell differentiation^[2]. GM-CSF R alpha monoclonal antibody decreases GM-CSFRα expression on GM-CSF-responsive cells and shows anti-inflammatory activity in rheumatoid arthritis (RA)^[3]. GM-CSF R alpha Protein, Human (HEK293, His) is a recombinant protein with a C-Terminal His label, It consists of 298 amino acids (E23-G320) and is produced in HEK293 cells.

GM-CSF R alpha is expressed on myeloid cells and on some non-hemopoietic cells, such as endothelial cells, not on T cells^[2].
The amino acid sequence of human GM-CSF R alpha protein has low homology for mouse GM-CSF R alpha protein.
GM-CSF receptor (GM-CSFR) consists of two subunits, an α-subunit, which binds the cytokine with low affinity, and a larger β-subunit (beta common; βc), responsible for signaling, forming a ternary receptor complex. Signal transduction in response to the cytokines interleukin (IL)-3 and IL-5 is also mediated by βc; therefore, receptor specificity is due to GM-CSFRα^[1]. After binding GM-CSF to its receptor, Janus-kinase-2 (JAK-2) is recruited to the cytoplasmic domain of the β chain, and activation of JAK-2 occurs, which subsequently induces STAT-5 phosphorylation. This signaling pathway induces migration of STAT-5 dimers to the nucleus and promotes the transcription of various genes such as pim-1 and CIS to induce cell differentiation^[2].
GM-CSFR α-subunit significantly increases positive synovial macrophages in the RA synovium. GM-CSFR α monoclonal antibody suppresses disease activity in the murine collagen-induced arthritis model^[3].

Measured by its ability to inhibit GM-CSF-dependent proliferation of TF-1 human erythroleukemic cells.The ED₅₀ for this effect is 0.5-2.509 μg/mL.

• 
  Measured by its ability to inhibit GM-CSF-dependent proliferation of TF-1 human erythroleukemic cells. The ED₅₀ for this effect is 2.509 μg/mL in the presence of 40 pg/mL of rhGM-CSF. corresponding to a specific activity is 398.5652 units/mg.

Human

HEK293

C-6*His

P15509 (E23-G320)

1438  [NCBI]

EKSDLRTVAPASSLNVRFDSRTMNLSWDCQENTTFSKCFLTDKKNRVVEPRLSNNECSCTFREICLHEGVTFEVHVNTSQRGFQQKLLYPNSGREGTAAQNFSCFIYNADLMNCTWARGPTAPRDVQYFLYIRNSKRRREIRCPYYIQDSGTHVGCHLDNLSGLTSRNYFLVNGTSREIGIQFFDSLLDTKKIERFNPPSNVTVRCNTTHCLVRWKQPRTYQKLSYLDFQYQLDVHRKNTQPGTENLLINVSGDLENRYNFPSSEPRAKHSVKIRAADVRILNWSSWSEAIEFGSDDGHHHHHH

Approximately 54-80 kDa due to the glycosylation.

• 
  Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder

Lyophilized after extensive dialysis against 20 mM PB,150 mM NaCl, pH 7.4 or PBS, pH 7.4, 8% trehalose.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Hansen G, et al. The structure of the GM-CSF receptor complex reveals a distinct mode of cytokine receptor activation. Cell. 2008 Aug 8;134(3):496-507.  [Content Brief]

  [2]. Martinez-Moczygemba M, et, al. Biology of common beta receptor-signaling cytokines: IL-3, IL-5, and GM-CSF. J Allergy Clin Immunol. 2003 Oct;112(4):653-65; quiz 666.  [Content Brief]

  [3]. Lotfi N, et al. Roles of GM-CSF in the Pathogenesis of Autoimmune Diseases: An Update. Front Immunol. 2019 Jun 4;10:1265.  [Content Brief]

  [4]. Goldstein JI, et, al. Defective leukocyte GM-CSF receptor (CD116) expression and function in inflammatory bowel disease. Gastroenterology. 2011 Jul;141(1):208-16.  [Content Brief]

  [5]. Cook AD, et al. Granulocyte macrophage colony-stimulating factor receptor α expression and its targeting in antigen-induced arthritis and inflammation. Arthritis Res Ther. 2016 Dec 1;18(1):287.  [Content Brief]