FYN and ABL Regulate the Interaction Networks of the DCBLD Receptor Family

Abstract

The Discoidin, CUB, and LCCL domain-containing protein (DCBLD) family consists of two type-I transmembrane scaffolding receptors, DCBLD1 and DCBLD2, which play important roles in development and cancer. The non-receptor tyrosine kinases FYN and ABL are known to drive phosphorylation of tyrosine residues in YXXP motifs within the intracellular domains of DCBLD family members, which leads to the recruitment of the Src homology 2 (SH2) domain of the adaptors CT10 regulator of kinase (CRK) and CRK-like (CRKL). We previously characterized the FYN- and ABL-driven phosphorylation of DCBLD family YXXP motifs. However, we have identified additional FYN- and ABL-dependent phosphorylation sites on DCBLD1 and DCBLD2. This suggests that beyond CRK and CRKL, additional DCBLD interactors may be regulated by FYN and ABL activity. Here, we report a quantitative proteomics approach in which we map the FYN- and ABL-regulated interactomes of DCBLD family members. We found FYN and ABL regulated the binding of several signaling molecules to DCBLD1 and DCBLD2, including members of the 14-3-3 family of adaptors. Biochemical investigation of the DCBLD2/14-3-3 interaction revealed ABL-induced binding of 14-3-3 family members directly to DCBLD2.

DCBLD1 is associated with the integrin signaling pathway and has prognostic value in non-small cell lung and invasive breast carcinoma

“…Previous in vitro experiments reveal that the DCBLD1 interactome consists mainly of adaptor proteins and proteins associated with actin dynamics 15 , further implicating a role for DCBLD1 in focal adhesions and supporting the idea that DCBLD1 is a NRP-like protein. Both NRP1 and NRP2 are involved in focal adhesions: NRP1 regulates focal adhesion turnover and NRP2 regulates α6β1 integrin association with the cytoskeleton 11 , 34 .…”

“…The intracellular region of DCBLD1 contains seven highly conserved YxxP motifs that are involved in phosphorylation-dependent binding to the CRKL signaling protein 14 . The Abl and Fyn kinases are responsible for this phosphorylation 14 , 15 . Phosphoprotemic bioinformatic analysis showed that the phosphorylation of four of these YxxP sites was altered following the inhibition of EGFR and MET and following HGF and FGF2 stimulation, suggesting an association of DCBLD1 with receptor tyrosine kinases 2 .…”

“…Phosphoprotemic bioinformatic analysis showed that the phosphorylation of four of these YxxP sites was altered following the inhibition of EGFR and MET and following HGF and FGF2 stimulation, suggesting an association of DCBLD1 with receptor tyrosine kinases 2 . Thus far, the only study on the interactome of DCBLD1 involved proteomic analysis on HEK 293 cells transfected with a FLAG-tagged DCBLD1 plasmid 15 . With this overexpression model, the FLAG immunoprecipitate revealed that the majority of DCBLD1 interactors were adaptor proteins and proteins associated with actin dynamics 15 .…”

“…Thus far, the only study on the interactome of DCBLD1 involved proteomic analysis on HEK 293 cells transfected with a FLAG-tagged DCBLD1 plasmid 15 . With this overexpression model, the FLAG immunoprecipitate revealed that the majority of DCBLD1 interactors were adaptor proteins and proteins associated with actin dynamics 15 .…”

Pan-cancer analyses identify DCBLD2 as an oncogenic, immunological, and prognostic biomarker

“…Reported literature has revealed that DCBLD2 influences the emergence and progression of multiple diseases, including cancer ( Kikuta et al, 2017 ; He et al, 2020 ; Alhamoudi et al, 2021 ; Coppo et al, 2021 ; Feng et al, 2021 ). Moreover, DCBLD2 has been found to interact with the receptor tyrosine kinases EGFR, VEGFR, PDGFR, and INSR ( Nie et al, 2013 ; Feng et al, 2014 ; Schmoker et al, 2019 ; Schmoker et al, 2020 ). Currently, no study has investigated whether DCBLD2 regulates the immune microenvironment and pathogenesis of tumors from the pan-cancer landscape.…”