Related Experiment Video
Updated: Aug 29, 2026

Defining Gene Functions in Tumorigenesis by Ex vivo Ablation of Floxed Alleles in Malignant Peripheral Nerve Sheath Tumor Cells
Published on: August 25, 2021
PKA phosphorylation and 14-3-3 interaction regulate the function of neurofibromatosis type I tumor suppressor,
Liping Feng1, Shunji Yunoue, Hiroshi Tokuo
1Department of Tumor Genetics and Biology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
Abstract:
Neurofibromin, a neurofibromatosis type I (NF1) tumor suppressor gene product, has a domain acting as a GTPase activating protein and functions in part as a negative regulator of Ras. Loss of neurofibromin expression in NF1 patients is associated with elevated Ras activity and increased cell proliferation. Therefore, regulation of the function of neurofibromin is heavily involved in cell growth and differentiation. In the present study, we identified a novel cellular neurofibromin-associating protein, 14-3-3, which belongs to a highly conserved family of proteins that regulate intracellular signal transduction events in all eukaryotic cells. The interaction of 14-3-3 is mainly directed to the C-terminal domain (CTD) of neurofibromin, and the cAMP-dependent protein kinase (PKA)-dependent phosphorylation clustered on CTD-Ser (2576, 2578, 2580, 2813) and Thr (2556) is required for the interaction. Interestingly, the increased phosphorylation and association of 14-3-3 negatively regulate the function of neurofibromin. These findings indicate that PKA phosphorylation followed by 14-3-3 protein interaction may modulate the biochemical and biological functions of neurofibromin.
Related Concept Videos
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
PI3K/mTOR/AKT Signaling Pathway
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Enzyme-linked Receptors
Phosphorylation
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Amplifying Signals via Enzymatic Cascade
