Csig-30. a Novel Interacting Partner for Pid1, a Growth Inhibitor in Pediatric and Adult Brain Tumors
Year: 2016
Type: conference-abstract
Abstract: PID1 is an inhibitor of insulin receptor signaling which we had reported to be a novel inhibitor of medulloblastoma and glioma cell growth, and whose mRNA level is highly correlated with survival across multiple independent datasets of these tumors. PID1 harbors a phosphotyrosine binding domain and is therefore predicted to interact with proteins harboring NPXY motifs. We therefore hypothesized that PID1 will interact with phosphotyrosine-binding (PTB) domain containing protein(s) that may be important in brain tumors, and will modulate its/their signaling. Here we report PID1 interactions with one of these proteins and determine its biological consequences. Experiments consisted of immunoprecipitations, transient transfections, and western blotting. Functionally, assays included cell culture, flow cytometry for proliferation using BrdU/7AAD and apoptosis using AnnexinV/7AAD. Plasmids were pCMV-AN-HA-PID1(2) or control or the protein of interest in pcDNA3.1. Cells used were glioblastoma, medulloblastoma, atypical teratoid rhabdoid (ATRT), HEK293, and cells deficient or intact in PID1. We demonstrate co-immunoprecipitation of PID1 with the interacting protein partner in HEK293T cells overexpressing both proteins and in native brain tumor cells with/without overexpression. While tyrosine phosphorylation of the NPXY motifs was not required for the interaction, mutating the kinase domain or overall inhibition of tyrosine phosphorylation inhibited this protein’s interaction with PID1. Different domains in PID1 differentially co-IPd with this protein. Interestingly, cells without PID1 showed increased growth factor-dependent tyrosine phosphorylation of this protein and increased growth factor-induced proliferation. These data point to PID1 as a novel interacting partner and regulator of this protein’s biological effects and signaling.
Source: Neuro-Oncology
Authors: Anat Erdreich-Epstein, Xiuhai Ren, Sean Robinson, Mark Frey
Language: English
Subfield: Genetics
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2586296471