Interaction Between CRIPT and PSD-95 Is Required for Proper Dendritic Arborization in Hippocampal Neurons

• Published in: Molecular neurobiology 2020-05, Vol.57 (5), p.2479-2493
• Main Authors: Omelchenko, Anton, Menon, Harita, Donofrio, Sarah G., Kumar, Gaurav, Chapman, Heidi M., Roshal, Joshua, Martinez-Montes, Eduardo R., Wang, Tiffany L., Spaller, Mark R., Firestein, Bonnie L.
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing - antagonists & inhibitors; Adaptor Proteins, Signal Transducing - genetics; Adaptor Proteins, Signal Transducing - physiology; Amino Acid Motifs; Animals; Binding, Competitive; Biomedical and Life Sciences; Biomedicine; Cell Biology; Cells, Cultured; Cytoskeleton; Dendritic branching; Dendritic spines; Dendritic Spines - physiology; Dendritic Spines - ultrastructure; Disks Large Homolog 4 Protein - physiology; Gene Knockdown Techniques; Hippocampus; Hippocampus - cytology; Microtubules; Microtubules - metabolism; Microtubules - ultrastructure; Neurobiology; Neurology; Neuronal Plasticity - physiology; Neurosciences; Postsynaptic density; Postsynaptic density proteins; Protein Binding; Protein Interaction Mapping; Rats; RNA Interference; RNA, Small Interfering - genetics
• ISSN: 0893-7648; 1559-1182
• DOI: 10.1007/s12035-020-01895-5

CRIPT, the cysteine-rich PDZ-binding protein, binds to the third PDZ domain of PSD-95 (postsynaptic density protein 95) family proteins and directly binds microtubules, linking PSD-95 family proteins to the neuronal cytoskeleton. Here, we show that overexpression of a full-length CRIPT leads to a modest decrease, and knockdown of CRIPT leads to an increase in dendritic branching in cultured rat hippocampal neurons. Overexpression of truncated CRIPT lacking the PDZ domain-binding motif, which does not bind to PSD-95, significantly decreases dendritic arborization. Conversely, overexpression of a full-length CRIPT significantly increases the number of immature and mature dendritic spines, and this effect is not observed when CRIPT∆PDZ is overexpressed. Competitive inhibition of CRIPT binding to the third PDZ domain of PSD-95 with PDZ3-binding peptides resulted in differential effects on dendritic arborization based on the origin of respective peptide sequence. These results highlight multifunctional roles of CRIPT during development and underscore the significance of the interaction between CRIPT and the third PDZ domain of PSD-95.