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.
Yu
J
J
Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, California 92037.
Shao
L E
LE
Lemas
V
V
Yu
A L
AL
Vaughan
J
J
Rivier
J
J
Vale
W
W
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