| abstract |
Isolated SMDF, isolated DNA encoding SMDF, and recombinant or synthetic methods of preparing SMDF are disclosed. SMDF contains a β-type EGF-like domain and a N-terminal sequence which is distinct from all neuregulins reported so far. SMDF, when expressed in recombinant cell culture, activates tyrosine phosphorylation of the HER2/neu receptor in human breast cancer cells and displays mitogenic activity on Schwann cells. Northern blot and in situ hybridization analysis show that SMDF differs from other neuregulins in that it is nervous tissue specific, and is very highly expresssed, in comparison to other neuregulins, in the human and rat spinal cord motor neurons and sensory neurons. |