FKBP12, the 12-kDa FK506-binding protein, is a physiologic regulator of the cell cycle

Bahman Aghdasi, Keqiang Ye, Adam Resnick, Alex Huang, Hyo Chol Ha, Xin Guo, Ted M. Dawson, Valina L. Dawson, Solomon H. Snyder

Research output: Contribution to journalArticlepeer-review

103 Scopus citations


FKBP12, the 12-kDa FK506-binding protein, is a ubiquitous abundant protein that acts as a receptor for the immunosuppressant drug FK506, binds tightly to intracellular calcium release channels and to the transforming growth factor β (TGF-β) type 1 receptor. We now demonstrate that cells from FKBP12-deficient (FKBP12-/-) mice manifest cell cycle arrest in G1 phase and that these cells can be rescued by FKBP12 transfection. This arrest is mediated by marked augmentation of p21(WAF1/CIP1) levels, which cannot be further augmented by TGF-β1. The p21 up-regulation and cell cycle arrest derive from the overactivity of TGF-β receptor signaling, which is normally inhibited by FKBP12. Cell cycle arrest is prevented by transfection with a dominant-negative TGF-β receptor construct. TGF-β receptor signaling to gene expression can be mediated by SMAD, p38, and ERK/MAP kinase (extracellular signal-regulated kinase/mitogen-activated protein kinase) pathways. SMAD signaling is down-regulated in FKBP12-/- cells. Inhibition of ERK/MAP kinase fails to affect p21 up-regulation. By contrast, activated phosphorylated p38 is markedly augmented in FKBP12-/- cells and the p21 up-regulation is prevented by an inhibitor of p38. Thus, FKBP12 is a physiologic regulator of cell cycle acting by normally down-regulating TGF-β receptor signaling.

Original languageEnglish (US)
Pages (from-to)2425-2430
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number5
StatePublished - Feb 27 2001

ASJC Scopus subject areas

  • General


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