Intramolecular dynamics within the N-Cap-SH3-SH2 regulatory unit of the c-Abl tyrosine kinase reveal targeting to the cellular membrane.
c-Abl is a key regulator of cell signaling and is under strict control via intramolecular interactions. In this study, we address changes in the intramolecular dynamics coupling within the c-Abl regulatory unit by presenting its N-terminal segment (N-Cap) with an alternative function in the cell as c-Abl becomes activated. Using small angle x-ray scattering, nuclear magnetic resonance, and confocal microscopy, we demonstrate that the N-Cap and the Src homology (SH) 3 domain acquire μs-ms motions upon N-Cap association with the SH2-L domain, revealing a stabilizing synergy between these segments. The N-Cap-myristoyl tether likely triggers the protein to anchor to the membrane because of these flip-flop dynamics, which occur in the μs-ms time range. This segment not only presents the myristate during c-Abl inhibition but may also trigger protein localization inside the cell in a functional and stability-dependent mechanism that is lost in Bcr-Abl(+) cells, which underlie chronic myeloid leukemia. This loss of intramolecular dynamics and binding to the cellular membrane is a potential therapeutic target.
From the Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Instituto Nacional de Biologia Estrutural e Bioimagem, Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, RJ and.
Guilherme A P
GA
de Oliveira
Elen G
EG
Pereira
Giulia D S
GD
Ferretti
Ana Paula
AP
Valente
Yraima
Y
Cordeiro
Jerson L
JL
Silva
D000818:Animals; D017209:Apoptosis; D002462:Cell Membrane / Q000378:metabolism*; D002522:Chlorocebus aethiops; D002845:Chromatography / Q000379:methods; D015971:Gene Expression Regulation, Enzymologic; D015973:Gene Expression Regulation, Leukemic; D057809:HEK293 Cells; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000201:enzymology* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism*; D012542:Scattering, Radiation; D015398:Signal Transduction; D013053:Spectrophotometry / Q000379:methods; D014709:Vero Cells; D014965:X-Rays; D018909:src Homology Domains
D016315:Proto-Oncogene Proteins c-abl
Chronic Myeloid Leukemia; Myristoylation; NMR; Protein Dynamics; Protein Structure; SAXS; Tyrosine Protein Kinase (Tyrosine Kinase); X-ray Scattering; c-Abl Protein