Related Experiment Video
Updated: Jun 10, 2026

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
Published on: October 27, 2020
Coupling of dephosphorylation and nuclear export of Smads in TGF-beta signaling
Fangyan Dai1, Xueyan Duan, Yao-Yun Liang
1Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
Abstract:
In eukaryotes, regulation of signaling mediators/effectors in the nucleus is one of the principal mechanisms that govern duration and strength of signaling. Smads are a family of structurally related intracellular proteins that serve as signaling effectors for transforming growth factor beta (TGF-beta) and TGF-beta-related proteins. Accumulating evidence demonstrates that Smads possess intrinsic nucleocytoplasmic shuttling capacity, which enables them to transmit TGF-beta signals from cell membrane to nucleus. We recently identified two important steps in the termination of nuclear Smad signaling. The first step is initiated by a serine/threonine phosphatase PPM1A that dephosphorylates Smad2/3 in the nucleus, thereby shutting down signaling capacity of phosphorylated Smad2/3. The second step involves nuclear export of dephosphorylated Smad2/3 with the aid of nuclear protein RanBP3 to terminate Smad signaling. This chapter introduces methods for examining nuclear export of Smad2/3 in TGF-beta signaling.
Related Concept Videos
TGF - β Signaling Pathway
Amplifying Signals via Enzymatic Cascade
The JAK-STAT Signaling Pathway
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Receptor Downregulation in MVBs
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
MAPK Signaling Cascades

