General Description
Synaptopodin is a proline-rich, actin-associated protein (100 kDa) is present in the post-synaptic density (PSD) in actin cytoskeleton. It is also present in the dendritic spines and differentiated podocytes. Synaptopodin contains a high amount of proline residues (~20%), which are evenly distributed along the protein sequence, thus virtually excluding the formation of globular domains. In particular, synaptopodin does not contain functional domains found in receptor clustering PSD proteins. Sequence comparison between human and mouse synaptopodin shows 84% identity. The exclusive site of synaptopodin expression in the telencephalon is restricted to specific areas of high synaptic plasticity, i.e. in the perykaria of the olfactory bulb, striatum, and hippocampus.
Biochem/physiol Actions
Synaptopodin is thought to play an important role in synaptic plasticity and is associated in the modulation of motility of actin in neuronal dendritic spines. The association of synaptopodin with the specialized actin system of renal podocyte foot processes suggests that it may play a role in actin cytoskeleton dynamics of these cellular extensions. Synaptopodin has been found to interact with α-actinin-4 and the tight junction protein Membrane-associated guanylate kinase inverted 1 (MAGI-1) in Madin-Darby Canine Kidney (MDCK) cells.
