CNTF

Ciliary neurotrophic factor (CNTF) is a polypeptide initially purified from chick embryo ocular tissue and identified as a trophic factor for embryonic chick ciliary parasympathetic neurons in culture. Subsequent studies have demonstrated that CNTF is a survival factor for additional neuronal cell types including: primary sensory neurons, motor neurons, basal forebrain neurons and type 2 astrocytes. CNTF has also been shown to prevent the degeneration of motor axons after axotomy. The cDNA for CNTF encodes a 200 amino acid residue polypeptide that lacks a signal sequence. CNTF is highly conserved across species and exhibits cross-species activities. Human and rat CNTF share approximately 83% homology in their protein sequence. CNTF is structurally related to IL6, IL11, LIF, and OSM. All of these four helix bundle cytokines share gp130 as a signal-transducing subunit in their receptor complexes. The cDNA for recombinant rat CNTF (Ala2–Met200) was cloned from total RNA of a rat embryo using standard protocols. Ciliary Neurotrophic Factor (CNTF) is a potent neural factor that was originally characterized as a survivability factor for chick ciliary neurons in vitro. More recently, CNTF has been shown to promote survivability and differentiation of other neuronal cell types. Rat CNTF is a 22.7 kDa protein containing 199 amino acid residues.

Cntf

25707

P20294

NP_037298.1

NM_013166.1

1q43

Rat

Rat

AFAEQTPLTLHRRDLCSRSIWLARKIRSDLTALMESYVKHQGLNKNINLDSVDGVPVASTDRWSEMTEAERLQENLQAYRTFQGMLTKLLEDQRVHFTPTEGDFHQAIHTLMLQVSAFAYQLEELMVLLEQKIPENEADGMPATVGDGGLFEKKLWGLKVLQELSQWTVRSIHDLRVISSHQMGISALESHYGAKDKQM

Rat CNTF should be reconstituted in PBS to a concentration of 0.1 mg/ml. This solution can be diluted in water or other buffered solutions.

< 0.1 ng per µg of CNTF

> 98% by SDS-PAGE

Measured in a cell proliferation assay using TF1 human erythroleukemic cells [Kitamura T et al, J Cell Physiol 140, 1989) . The ED50 for this effect is typically 3 - 15 ng/mL.

199

Lyophilized

5 mM sodium acetate, pH 6.5

PBS

22.7 kDa

The lyophilized powder although stable at room temperature for 3 weeks, is best stored desiccated at -20°C. Reconstituted rat CNTF should be stored in working aliquots at -20°C. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA) .

E. coli