Membrane-associated neurotransmitter stimulating factor is very similar to ciliary neurotrophic factor.
Membrane-associated neurotransmitter stimulating factor (MANS) can modulate sympathetic neurotransmitter expression and promote ciliary neuron survival in cell culture. Previous studies have shown that its biological effects and biochemical properties are similar to those of ciliary neurotrophic factor (CNTF). In addition, CNTF is present in spinal cord, the source of MANS. These observations raised the possibility that MANS preparations contain CNTF. We find that partially purified MANS fractions contain a 24-kD protein that is recognized in Western blots by an antiserum generated against recombinant rat CNTF (rCNTF). This antiserum immunoprecipitates virtually all the cholinergic-inducing and the ciliary neurotrophic activities present in MANS preparations. When iodinated rCNTF is incubated with spinal cord membranes, a significant proportion of the labeled CNTF segregates with the membrane pellet. The membrane-associated exogenous CNTF can be eluted from the membrane fraction by treatment with high-salt solutions, similar to that used to solubilize MANS from spinal cord membranes. Our data suggest that a substantial portion of the cholinergic differentiation and ciliary neurotrophic activities present in MANS preparations can be attributed to CNTF or a CNTF-like molecule.
Rao
M
M
Department of Neuroscience, Case Western Reserve University, Cleveland, Ohio 44106.
Patterson
P H
PH
Landis
S C
SC
D000818:Animals; D000906:Antibodies / Q000276:immunology; D015153:Blotting, Western; D002462:Cell Membrane / Q000737:chemistry; D002478:Cells, Cultured; D020934:Ciliary Neurotrophic Factor; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D009474:Neurons / Q000737:chemistry; D011233:Precipitin Tests; D051381:Rats; D011994:Recombinant Proteins / Q000276:immunology
D000906:Antibodies; D020934:Ciliary Neurotrophic Factor; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins