The present invention relates to novel cytoplasmic tyrosine kinases isolated
from megakaryocytes (megakaryocyte kinases or MKKs) which are involved in cellular
signal transduction pathways and to the use of these novel proteins in the diagnosis
and treatment of disease. The present invention further relates to specific megakaryocyte
kinases, designated MKK1, MKK2, and MKK3, and their use as diagnostic and therapeutic agents.
