Purkinje cell protein 4-like protein 1 (PCP4L1)

Purkinje cell protein 4-like protein 1 (PCP4L1) is a small neuronal protein characterized by the presence of an IQ motif, a domain known for calmodulin binding[4][5][7]. PCP4L1 is closely related to Purkinje cell protein 4 (PCP4/PEP-19), but exhibits distinct biochemical properties: the full-length human or mouse PCP4L1 protein does not bind calmodulin under physiological conditions due to an internal auto-inhibitory element that suppresses the IQ motif’s function, although the isolated IQ motif can bind calmodulin and inhibit calmodulin-dependent kinase II[4]. PCP4L1 expression is CNS-specific during development, with strong expression in the roof plate of the midbrain and hindbrain, circumventricular organs, choroid plexus, and pineal gland[7]. The evolutionary conservation and developmental expression pattern suggest a role in regional brain patterning and neurodevelopment[7]. Unlike its paralog PCP4, PCP4L1’s role as a therapeutic, diagnostic, or prognostic target is unclear. No interacting drugs or approved therapeutic interventions targeting PCP4L1 are currently documented, and no direct human disease links or biomarker roles have been established to date. The current understanding of its mechanism posits PCP4L1 as a latent modulator of calmodulin-dependent signaling, potentially regulated by post-translational modifications or cofactors[4][5].

Other names

IQ motif containing protein 1 (IQM1)PCP4-like protein 1PCP4L1