Restrictin-P: the first member of a putative family of novel inhibitors.
MBA-2.1 cells produce an activity, designated restrictin-P, which is specifically inhibitory to the growth of plasmacytomas and mature B cell lymphomas. We examined whether the activity of this stromally derived glycoprotein could be attributed to a well-characterized growth factor. Restrictin-P-producing cells were therefore screened for the expression of transcripts of a variety of growth suppressors. With the exception of TGF-beta 1, none was produced in detectable amounts by these cells. Furthermore, recombinant forms of the inhibitory molecules tested did not exert a biological effect similar to that of restrictin-P. Restrictin-P was shown to elicit a G0/G1 arrest in the cell cycle of its target cells, as soon as 24 h after their exposure to the inhibitor. This effect could not be mimicked by TGF-beta 1. We suggest that restrictin-P is part of a novel family of inhibitors which are required for the maintenance of cell-type specificities in the hematopoietic microenvironment.
Honigwachs-Sha'anani
J
J
Department of Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
Brosh
N
N
Kompier
R
R
Kadouri
A
A
Zipori
D
D
D000818:Animals; D002453:Cell Cycle / Q000187:drug effects*; D002460:Cell Line; D016207:Cytokines / Q000235:genetics; D005434:Flow Cytometry; D006023:Glycoproteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D006131:Growth Inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D036341:Intercellular Signaling Peptides and Proteins; D010954:Plasmacytoma; D012333:RNA, Messenger / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D016207:Cytokines; D006023:Glycoproteins; D006131:Growth Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; C069698:restrictin-P