| Structural highlights
Function
1433Z_HUMAN Adapter protein implicated in the regulation of a large spectrum of both general and specialized signaling pathways. Binds to a large number of partners, usually by recognition of a phosphoserine or phosphothreonine motif. Binding generally results in the modulation of the activity of the binding partner.[1] [2] [3] [4] [5]
Publication Abstract from PubMed
The Ras-RAF-MEK-ERK signaling axis, commonly mutated in human cancers, is highly regulated to prevent aberrant signaling in healthy cells. One of the pathway modulators, 14-3-3, a constitutive dimer, induces RAF dimerization and activation by binding to a phosphorylated motif C-terminal to the RAF kinase domain. Recent work has suggested that a C-terminal "DTS" region in BRAF is necessary for this 14-3-3-mediated activation. We show that the catalytic activity and ATP binding affinity of the BRAF:14-3-3 complex is insensitive to the presence or absence of the DTS, while the ATP sites of both BRAF molecules are identical and available for binding. We also present a crystal structure of the apo BRAF:14-3-3 complex showing that the DTS is not required to attain the catalytically active conformation of BRAF. Rather, BRAF dimerization induced by 14-3-3 is the key step in activation, allowing the active BRAF:14-3-3 tetramer to achieve catalytic activity comparable to the constitutively active oncogenic BRAF V600E mutant.
Dimerization Induced by C-Terminal 14-3-3 Binding Is Sufficient for BRAF Kinase Activation.,Liau NPD, Venkatanarayan A, Quinn JG, Phung W, Malek S, Hymowitz SG, Sudhamsu J Biochemistry. 2020 Oct 2. doi: 10.1021/acs.biochem.0c00517. PMID:32970425[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Dubois T, Rommel C, Howell S, Steinhussen U, Soneji Y, Morrice N, Moelling K, Aitken A. 14-3-3 is phosphorylated by casein kinase I on residue 233. Phosphorylation at this site in vivo regulates Raf/14-3-3 interaction. J Biol Chem. 1997 Nov 14;272(46):28882-8. PMID:9360956
- ↑ Zheng W, Zhang Z, Ganguly S, Weller JL, Klein DC, Cole PA. Cellular stabilization of the melatonin rhythm enzyme induced by nonhydrolyzable phosphonate incorporation. Nat Struct Biol. 2003 Dec;10(12):1054-7. Epub 2003 Oct 26. PMID:14578935 doi:10.1038/nsb1005
- ↑ Tsuruta F, Sunayama J, Mori Y, Hattori S, Shimizu S, Tsujimoto Y, Yoshioka K, Masuyama N, Gotoh Y. JNK promotes Bax translocation to mitochondria through phosphorylation of 14-3-3 proteins. EMBO J. 2004 Apr 21;23(8):1889-99. Epub 2004 Apr 8. PMID:15071501 doi:10.1038/sj.emboj.7600194
- ↑ Ganguly S, Weller JL, Ho A, Chemineau P, Malpaux B, Klein DC. Melatonin synthesis: 14-3-3-dependent activation and inhibition of arylalkylamine N-acetyltransferase mediated by phosphoserine-205. Proc Natl Acad Sci U S A. 2005 Jan 25;102(4):1222-7. Epub 2005 Jan 11. PMID:15644438 doi:0406871102
- ↑ Gu YM, Jin YH, Choi JK, Baek KH, Yeo CY, Lee KY. Protein kinase A phosphorylates and regulates dimerization of 14-3-3 epsilon. FEBS Lett. 2006 Jan 9;580(1):305-10. Epub 2005 Dec 19. PMID:16376338 doi:S0014-5793(05)01485-7
- ↑ Liau NPD, Venkatanarayan A, Quinn JG, Phung W, Malek S, Hymowitz SG, Sudhamsu J. Dimerization Induced by C-Terminal 14-3-3 Binding Is Sufficient for BRAF Kinase Activation. Biochemistry. 2020 Oct 20;59(41):3982-3992. PMID:32970425 doi:10.1021/acs.biochem.0c00517
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