Heavy chain of cytoplasmic dynein is a major component of the postsynaptic density fraction

Abstract

A protein with an apparent molecular size of 490 kDa was found in the postsynaptic density (PSD) fraction isolated from porcine cerebral cortices and rat forebrains, and this 490 kDa protein accounted for $3% of the total protein of these samples. Matrix-assisted laser desorption ionization-time of flight mass spectrometric and Western blotting analyses consistently indicated that this 490 kDa protein consisted primarily of the heavy chain of cytoplasmic dynein (cDHC). Immunocytochemical analyses showed that cDHC was found in 92% and 89% of the phalloidin-positive protrusions that were themselves associated with discrete clusters of synaptophysin, a presynaptic terminal marker, and PSD-95, a postsynaptic marker, on neuronal processes, respectively. Quantitative Western blotting analyses of various subcellular fractions isolated from porcine cerebral cortices and rat forebrains further showed that not only the heavy but also the intermediate chains of dynein are enriched in the PSD fraction. Cytoplasmic dynein is a microtubule-associated motor protein complex that drives the movement of various cargos toward the minus ends of microtubules and plays many other diverse functions in the cell. Our results that cDHC is a major component of the PSD fraction, that both dynein heavy and intermediate chains are enriched in the PSD fraction and that cDHC is present in dendritic spines raise the possibilities that cytoplasmic dynein may play structural and functional roles in the postsynaptic terminal. V V C 2006 Wiley-Liss, Inc.

Integrated Protein Array Screening and High Throughput Validation of 70 Novel Neural Calmodulin-binding Proteins

“…For example, semaphorin 3A signaling pathways have been shown to play an important role in the regulation of dendritic spine maturation in cerebral cortex neurons (44,45). Dynein heavy chain is proposed to be a major component of PSD and is present in dendritic spines, raising the possibility that cytoplasmic dynein plays structural and functional roles in the postsynaptic terminal (46).…”

Proprioceptive Sensory Neuropathy in Mice with a Mutation in the Cytoplasmic Dynein Heavy Chain 1 Gene

“…Similarly, the abrogation of these essential functions by the Swl mutation most likely accounts for the late implantation or early gastrulation lethal phenotype in Swl/Swl embryos. Studies have also shown that this motor protein is involved in multiple neuronspecific processes, such as neuronal migration (Sasaki et al, 2000), the growth and development of neuritis (Barakat-Walter and Riederer, 1996), synapse formation (Cheng et al, 2006), as well as axonal transport of microtubules, neurofilaments (He et al, 2005) and organelles (Schnapp et al, 1989). Among them, the axonal transport role of cytoplasmic dynein has recently been associated with motor neuron survival Puls et al, 2005).…”

A Study of the Spatial Protein Organization of the Postsynaptic Density Isolated from Porcine Cerebral Cortex and Cerebellum

“…It has been recently reported that certain PSD proteins, including tubulins, CaMKII␣, CaMKII␤, MAP2, and cDHC, would exit from dendritic spines of cultured rat hippocampal neurons when these neurons are kept at low temperature for a few minutes or treated with drugs either disrupting actin cytoskeleton (87) or with drugs inducing calcium release from internal stores (Cheng and Chang unpublished results). On the other hand, the same treatments do not affect the localization of PSD-95 or glutamate receptors in dendritic spines.…”

“…The uuPSD sample was then subject to immunoab- sorption by using protein G-magnetic beads containing covalently linked antibodies to CaMKII␣, EF1␣, PSD-95, and ␣-tubulin. It has been reported that CaMKII␣ and ␣-tubulin are abundant in the PSD (61) and that PSD-95 is a major scaffold protein of the PSD (62). EF1␣, a moonlighting protein proposed to regulate the actin and microtubule cytoskeleton (63,64), is also a prominent component in the PSD (19,22,65).…”

“…9 may work in concert with others, such as those found in the proteomic studies of proteins associated to various glutamate receptors, PSD-95 and ProSAP/shank proteins (35)(36)(37)(38)86), during the process of PSD structure organization. Recent quantitative analyses have consistently indicated that the proteins that have been implicated earlier to participate in the organization of PSD structures account for small fractions of the mass of the PSD (27,29,87). For example, the two most abundant ones of these proteins, CaMKII␣ and PSD-95, account for 3.6% and 0.8% of the protein mass of the PSD isolated by conventional biochemical procedures, respectively (27).…”