Publication Date
9-1-2024
Journal
PNAS Nexus
DOI
10.1093/pnasnexus/pgae401
PMID
39319326
PMCID
PMC11421662
PubMedCentral® Posted Date
9-12-2024
PubMedCentral® Full Text Version
Post-print
Published Open-Access
yes
Keywords
triple-negative breast cancer, DAPK3, migration, invasion, epithelial-to-mesenchymal transition
Abstract
Sixteen patient-derived xenografts (PDXs) were analyzed using a mass spectrometry (MS)-based kinase inhibitor pull-down assay (KIPA), leading to the observation that death-associated protein kinase 3 (DAPK3) is significantly and specifically overexpressed in the triple-negative breast cancer (TNBC) models. Validation studies confirmed enrichment of DAPK3 protein, in both TNBC cell lines and tumors, independent of mRNA levels. Genomic knockout of DAPK3 in TNBC cell lines inhibited in vitro migration and invasion, along with down-regulation of an epithelial–mesenchymal transition (EMT) signature, which was confirmed in vivo. The kinase and leucine-zipper domains within DAPK3 were shown by a mutational analysis to be essential for functionality. Notably, DAPK3 was found to inhibit the levels of desmoplakin (DSP), a crucial component of the desmosome complex, thereby explaining the observed migration and invasion effects. Further exploration with immunoprecipitation–mass spectrometry (IP–MS) identified that leucine-zipper protein 1 (LUZP1) is a preferential binding partner of DAPK3. LUZP1 engages in a leucine-zipper domain–mediated interaction that protects DAPK3 from proteasomal degradation. Thus, the DAPK3/LUZP1 heterodimer emerges as a newly discovered regulator of EMT/desmosome components that promote TNBC cell migration.
Included in
Biochemistry, Biophysics, and Structural Biology Commons, Biological Phenomena, Cell Phenomena, and Immunity Commons, Biology Commons, Oncology Commons
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