The invention concerns a novel neuregulin related ligand (NRG3) including
fragments and variants thereof, as new members of the neuregulin family
of compounds. The invention also concerns methods and means for producing
NRG3. The native polypeptides of the invention are characterized by
containing an extracellular domain including an EGF-like domain, a
transmembrane domain and a cytoplasmic domain. Isolated nucleotide
sequences encoding such polypeptides, expression vectors containing the
nucleotide sequences, recombinant host cells transformed with the
vectors, and methods for the recombinant production for the novel NRG3s
are also within the scope of the invention.