STAT1 Protein, Human (sf9, His-GST)

STAT1 is a signal transducer and activator of transcription that responds to interferons, KITLG/SCF, and growth factors. After type I IFN binds, STAT1 and STAT2 form ISGF3, which translocates to the nucleus and activates ISG transcription. STAT1 Protein, Human (sf9, His-GST) is the recombinant human-derived STAT1 protein, expressed by Sf9 insect cells , with N-10*His, N-GST labeled tag.

STAT1 is a signal transducer and transcription activator that plays a crucial role in mediating cellular responses to interferons (IFNs), cytokine KITLG/SCF, and various growth factors. Upon binding of type I IFN (IFN-alpha and IFN-beta) to cell surface receptors, STAT1 undergoes tyrosine phosphorylation and forms a dimer with STAT2. This complex, known as ISGF3 transcription factor, translocates to the nucleus and activates the transcription of IFN-stimulated genes (ISG), establishing an antiviral state. In response to type II IFN (IFN-gamma), STAT1 is phosphorylated at both tyrosine and serine residues, forming a homodimer (GAF) that enters the nucleus and binds to the IFN-gamma activated sequence (GAS), driving the expression of target genes and inducing a cellular antiviral state. Additionally, STAT1 becomes activated in response to KITLG/SCF and KIT signaling and may mediate cellular responses to activated FGFR1, FGFR2, FGFR3, and FGFR4. Furthermore, in the small intestine, STAT1 associates with Gasdermin-D and promotes the transcription of CIITA, inducing the formation of type 1 regulatory T (Tr1) cells. STAT1 interacts with various proteins, including PIAS1, IFNAR1, IFNAR2, NMI, CREBBP/CBP, PTK2/FAK1, SRC, ERBB4, PARP9, DTX3L, EP300/p300, and IFNGR1, contributing to its diverse cellular functions.

Measured in a cytotoxicity assay using HepG2 cells. The ED₅₀ for this effect is 3.292 μg/mL, corresponding to a specific activity is 303.767 units/mg.

Human

Sf9 insect cells

N-10*His;N-GST

P42224-2 (M1-V712)

6772  [NCBI]

Approximately 105-110 kDa

Greater than 90% as determined by reducing SDS-PAGE.

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of 20 mM Tris, 500 mM NaCl, pH 7.4. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years from date of receipt. 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.