Human granulocyte colony-stimulating factor specifically binds to murine
myeloblastic NFS-60 cells and activates their guanosine triphosphate
binding proteins/adenylate cyclase system
S Matsuda, N Shirafuji and S Asano
Department of Pathological Pharmacology, University of Tokyo, Japan.
The specific binding of human granulocyte colony-stimulating factor (G-
CSF) to its receptors on NFS-60 cells acts as a primer for cellular
proliferation. There are approximately 400 binding sites per cell, with a
binding constant of about 100 pmol/L. Before the proliferative response,
the affinity constant of the membrane particulate fraction to 35S-labeled
guanosine triphosphate-gamma-S (35S-GTP gamma S) and the intracellular
cyclic adenylate monophosphate (cAMP) level increased in the presence of
G-CSF to about 2.5-fold and about fivefold higher, respectively, than the
levels seen in the absence of G-CSF. The increases were time-dependent,
with a peak occurring 15 minutes after the addition of G-CSF at 37 degrees
C. These findings suggest that, following the binding of the G-CSF to its
surface receptors, the activation of the guanosine triphosphate
(GTP)-binding protein/adenylate cyclase system may be involved in the
proliferation of immature myeloid cells.
Volume 74,
Issue 7,
pp. 2343-2348,
11/15/1989
Copyright © 1989 by The American Society of Hematology
