GRIPAP1 (GRIP1 associated protein 1) functions as a scaffold protein that facilitates MAP3K1/MEKK1-mediated activation of JNK1 kinase signaling pathways. At synapses, GRIPAP1 plays a crucial role in AMPA receptor trafficking and endocytic recycling, with its protein levels regulated by the E3 ubiquitin ligase UBE3A through polyubiquitination and proteasomal degradation 1. Loss of UBE3A function, as occurs in Angelman syndrome, leads to increased GRIPAP1 abundance, potentially contributing to impaired synaptic plasticity 1. GRIPAP1 expression is dysregulated in several disease contexts. In temporal lobe epilepsy with hippocampal sclerosis, GRIPAP1 is part of a circRNA-mRNA co-expression network that may contribute to disease pathogenesis 2. The gene shows altered expression in early Parkinson's disease, suggesting potential as a biomarker 3. Additionally, GRIPAP1 can serve as a fusion partner in translocation renal cell carcinomas, where GRIPAP1-TFE3 fusions have been identified 4. In breast cancer metastasis, GRIPAP1 expression is enhanced by specific tRNA upregulation, promoting metastatic progression 5. These findings highlight GRIPAP1's importance in synaptic function and its involvement in various neurological and oncological disorders.