Cloning and Characterization of the Human Homolog of Mouse Jak2
Ilan Dalal,
Enrico Arpaia,
Harjit Dadi,
Shaila Kulkarni,
Jerami Squire, and
Chaim M. Roifman
From the Division of Immunology/Allergy, Department of Pediatrics,
and the Department of Pathology, University of Toronto and the The
Hospital for Sick Children, Toronto, Ontario, Canada.
Members of the Jak family play a critical role in signal
transduction mediated by cytokine and hormone receptors. In this study,
we report the cloning and characterization of human Jak2. The predicted
amino acid sequence shows 91% homology to the described murine Jak2,
but with a significant difference in the extreme C-terminal sequence.
Using the human cDNA as a probe, we localized the gene for human Jak2
to chromosome 9p23-24. Human Jak2 mRNA is highly expressed in the
spleen, lymph nodes, and peripheral blood lymphocytes (PBLs). A
polyclonal antibody raised against the unique C-terminus of human Jak2
was used to characterize Jak2 protein. Levels of Jak2 protein
expression increased significantly in mitogen- and anti-IgM-stimulated
B cells and to a lesser degree in activated T cells. In addition, high
levels of Jak2 protein were detected in pre-B leukemia cells.
Blood, Vol. 91 No. 3 (February 1), 1998:
pp. 844-851
© 1998 by The American Society of Hematology.
