Synaptopodin (SYNPO)

Synaptopodin is a proline-rich, actin-associated protein found principally in the dendritic spines of telencephalic neurons and in differentiated renal podocytes[1][4][7]. In neurons, synaptopodin is essential for the formation of the spine apparatus, a subcellular organelle made of stacked smooth endoplasmic reticulum cisternae, which supports local calcium signaling and protein synthesis crucial for synaptic plasticity[3][5][6]. Synaptopodin is expressed mainly in regions of the brain with high synaptic plasticity, such as the olfactory bulb, cerebral cortex, striatum, and hippocampus[1][4]. In the kidney, it modulates podocyte structure and function, and its expression is critical for podocyte foot processes and glomerular filtration barrier integrity[4][7][8]. Its gene name is SYNPO, and its protein structure is largely unstructured, with high proline content and several phosphorylation sites, facilitating interactions with other cytoskeletal and signaling proteins[1][5][6]. Although changes in synaptopodin levels are implicated in neurodegenerative disorders (e.g., Alzheimer's) and kidney diseases, it is not considered a classical drug target (receptor, enzyme, transporter), but rather a structural protein influencing cellular architecture and signaling[4][3][7].