Protein piccolo is a protein that in humans is encoded by the PCLO gene.

Synaptic vesicles dock and fuse in the active zone of the plasma membrane at chemical synapses. The presynaptic cytoskeletal matrix (PCM), which is associated with the active zone and is situated between synaptic vesicles, is thought to be involved in maintaining the neurotransmitter release site in register with the postsynaptic reception apparatus. The cycling of synaptic vesicles is a multistep process involving a number of proteins (see MIM 603215). Among the components of the PCM that orchestrate these events are Bassoon (BSN; MIM 604020), RIM (RBBP8; MIM 604124), Oboe, and Piccolo (PCLO).[supplied by OMIM]. Sequence Note: This RefSeq record was created from transcript and genomic sequence data because no single transcript was available for the full length of the gene. The extent of this transcript is supported by transcript alignments. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Gene record to access additional publications.
Function: May act as a scaffolding protein involved in the organization of synaptic active zones and in synaptic vesicle trafficking (By similarity).