Importance of FSH-releasing protein and inhibin in erythrodifferentiation.
Inhibin is a hypophysiotropic hormone which selectively suppresses the secretion of pituitary follicle-stimulating hormone. It has been isolated from gonadal fluids and characterized as a protein heterodimer consisting of an alpha subunit and one of two beta subunits (beta A or beta B). FSH-releasing protein (FRP), also named activin, is a dimer consisting of two inhibin beta-chains. A factor from conditioned medium of a leukaemia cell line has been isolated which can induce mouse Friend cells to become benzidine-positive, and which shares a similar N-terminal sequence with porcine FRP. In this report, we find that FRP and inhibin modulate both the induction of haemoglobin accumulation in a human erythroleukaemic cell line, K562, and the proliferation of erythroid progenitor cells in human bone marrow culture. These two proteins could constitute a novel humoral regulatory control of erythropoiesis which would involve two types of related protein dimers with functionally opposite effects.
Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, California 92037.
J
J
Yu
L E
LE
Shao
V
V
Lemas
A L
AL
Yu
J
J
Vaughan
J
J
Rivier
W
W
Vale
D028341:Activins; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D004920:Erythropoiesis / Q000187:drug effects*; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007265:Inhibins / Q000494:pharmacology*
D028341:Activins; D007265:Inhibins