Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA.
Neuroscience Graduate Program, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA.
Mol Neurobiol. 2020 May;57(5):2479-2493. doi: 10.1007/s12035-020-01895-5. Epub 2020 Mar 9.
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.
CRIPT 是一种富含半胱氨酸的 PDZ 结合蛋白，可与 PSD-95（突触后密度蛋白 95）家族蛋白的第三个 PDZ 结构域结合，并直接结合微管，将 PSD-95 家族蛋白与神经元细胞骨架连接起来。在这里，我们发现全长 CRIPT 的过表达会导致树突分支适度减少，而 CRIPT 的敲低会导致培养的大鼠海马神经元树突分支增加。缺乏 PDZ 结构域结合基序的截断 CRIPT 的过表达，该基序不与 PSD-95 结合，会显著减少树突分支。相反，全长 CRIPT 的过表达会显著增加不成熟和成熟树突棘的数量，而当过表达 CRIPT∆PDZ 时则不会观察到这种效果。PDZ3 结合肽竞争性抑制 CRIPT 与 PSD-95 的第三个 PDZ 结构域的结合，根据各自肽序列的来源，对树突分支产生不同的影响。这些结果突出了 CRIPT 在发育过程中的多功能作用，并强调了 CRIPT 与 PSD-95 的第三个 PDZ 结构域之间相互作用的重要性。
