Association of Protein Phosphatase 1γ1 with Spinophilin Suppresses Phosphatase Activity in a Parkinson Disease Model

Brown, A. C.; Baucum, Anthony J.; Bass, Martha A.; Colbran, Roger J.

doi:10.1074/jbc.m801377200

Cited by 31 publications

(41 citation statements)

References 58 publications

(110 reference statements)

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“…Although their homologues are 80% identical in amino sequence, they still exhibit distinct functions. For example, PP1␣ is essential for the formation of synaptic plasticity and memory processes (35); PP1␤ was found to attenuate Ca 2ϩ transients in cardiomyocytes (1); and PP1␥ mediates the striatal dopamine depletion-induced hyperphosphorylation of synaptic proteins in brain (3). However, how these isoforms are involved in cardiac dysfunction is not clear.…”

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confidence: 99%

PP1γ functionally augments the alternative splicing of CaMKIIδ through interaction with ASF

Huang

Cao

Liao

et al. 2014

American Journal of Physiology-Cell Physiology

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W. PP1␥ functionally augments the alternative splicing of CaMKII␦ through interaction with ASF. Am J Physiol Cell Physiol 306: C167-C177, 2014. First published November 6, 2013 doi:10.1152/ajpcell.00145.2013.-Protein phosphatase 1 (PP1) and Ca 2ϩ /calmodulin-dependent protein kinase ␦ (CaMKII␦) are upregulated in heart disorders. Alternative splicing factor (ASF), a major splice factor for CaMKII␦ splicing, can be regulated by both protein kinase and phosphatase. Here we determine the role of PP1 isoforms in ASF-mediated splicing of CaMKII␦ in cells. We found that 1) PP1␥, but not ␣ or ␤ isoform, enhanced the splicing of CaMKII␦ in HEK293T cells; 2) PP1␥ promoted the function of ASF, evidenced by the existence of ASF-PP1␥ association as well as the PP1␥ overexpression-or silencing-mediated change in CaMKII␦ splicing in ASFtransfected HEK293T cells; 3) CaMKII␦ splicing was promoted by overexpression of PP1␥ and impaired by application of PP1 inhibitor 1 (I1PP1) or pharmacological inhibitor tautomycetin in primary cardiomyocytes; 4) CaMKII␦ splicing and enhancement of ASF-PP1␥ association induced by oxygen-glucose deprivation followed by reperfusion (OGD/R) were potentiated by overexpression of PP1␥ and suppressed by inhibition of PP1␥ with I1PP1 or tautomycetin in primary cardiomyocytes; 5) functionally, overexpression and inhibition of PP1␥, respectively, potentiated or suppressed the apoptosis and Bax/Bcl-2 ratio, which were associated with the enhanced activity of CaMKII in OGD/R-stimulated cardiomyocytes; and 6) CaMKII was required for the OGD/R induced-and PP1␥ exacerbated-apoptosis of cardiomyocytes, evidenced by a specific inhibitor of CaMKII KN93, but not its structural analog KN92, attenuating the apoptosis and Bax/Bcl-2 ratio in OGD/R and PP1␥-treated cells. In conclusion, our results show that PP1␥ promotes the alternative splicing of CaMKII␦ through its interacting with ASF, exacerbating OGD/R-triggered apoptosis in primary cardiomyocytes.protein phosphatase 1␥; alternative splicing factor; CaMKII␦C; splicing; cardiomyocytes

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confidence: 99%

PP1γ functionally augments the alternative splicing of CaMKIIδ through interaction with ASF

Huang

Cao

Liao

et al. 2014

American Journal of Physiology-Cell Physiology

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“…Alterations in dendritic morphology and/or the number of dendritic spines have been linked to numerous neurological disorders, including PD, Angelman syndrome, and fragile X syndrome (3)(4)(5)(6)(7), and the interaction between spinophilin and PP1␥1 is altered in an animal model of PD (17). Our data suggest that a novel spinophilin complex(es) associated with neurofilaments and/or motor proteins may be important for physiological and pathological regulation of dendritic morphology and other dendritic processes.…”

Section: Discussionmentioning

confidence: 81%

“…Co-immunoprecipitations-Solubilized extracts from 1) mouse striata prepared for fractionation studies (S1, S2, or S3) in isotonic or low ionic strength buffer, 2) mouse whole brain homogenized in isotonic (1% Triton X-100 and 1% sodium deoxycholate) or low ionic strength (1% Triton X-100) buffer, or 3) rat or mouse striata or transfected HEK293 cells (see below) prepared directly in low ionic strength buffer containing 0.5-1.0% Triton X-100 were immunoprecipitated essentially as described (17). Antibody concentrations used were as follows: goat spinophilin, 4 -8 g; rabbit spinophilin, 7.5-30 g; mouse spinophilin, 2.5-15 g; rabbit ␣-actinin, 12 g; and appropriate nonimmune IgG control of a similar concentration.…”

Section: Methodsmentioning

confidence: 99%

“…Densitometric analyses were performed using NIH Image J. To quantify co-immunoprecipitations from control and DA-depleted striatum, immunoreactivity in the DAdepleted pellet was divided by immunoreactivity in the control pellet, and -fold changes in co-precipitating proteins were compared to 1 using either a one-column t test or, if normality was not met or the n was too low to test for normality, a Wilcoxon signed rank test (see (17) for details).…”

Section: Methodsmentioning

confidence: 99%

“…Spinophilin associates with its homolog neurabin, which is also a PP1-and F-actin-binding protein that regulates synaptic plasticity and dendrite morphology (14 -16). The interaction between spinophilin and the ␥1 isoform of PP1 is enhanced in an animal model of PD (17), perhaps contributing to the altered phosphorylation of synaptic proteins, such as CaMKII and glutamate receptor subunits observed following dopamine (DA) depletion (18 -20). DA depletion also decreases the number of dendritic spines on striatal medium spiny neurons (4,5).…”

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confidence: 99%

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Identification and Validation of Novel Spinophilin-associated Proteins in Rodent Striatum Using an Enhanced ex Vivo Shotgun Proteomics Approach

Baucum

Jalan‐Sakrikar

Jiao

et al. 2010

Molecular & Cellular Proteomics

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Spinophilin regulates excitatory postsynaptic function and morphology during development by virtue of its interactions with filamentous actin, protein phosphatase 1, and a plethora of additional signaling proteins. To provide insight into the roles of spinophilin in mature brain, we characterized the spinophilin interactome in subcellular fractions solubilized from adult rodent striatum by using a shotgun proteomics approach to identify proteins in spinophilin immune complexes. Initial analyses of samples generated using a mouse spinophilin antibody detected 23 proteins that were not present in an IgG control sample; however, 12 of these proteins were detected in complexes isolated from spinophilin knock-out tissue. A second screen using two different spinophilin antibodies and either knock-out or IgG controls identified a total of 125 proteins. The probability of each protein being specifically associated with spinophilin in each sample was calculated, and proteins were ranked according to a 2 analysis of the probabilities from analyses of multiple samples. Spinophilin and the known associated proteins neurabin and multiple isoforms of protein phosphatase 1 were specifically detected. Multiple, novel, spinophilin-associated proteins (myosin Va, calcium/calmodulin-dependent protein kinase II, neurofilament light polypeptide, postsynaptic density 95, ␣-actinin, and densin) were then shown to interact with GST fusion proteins containing fragments of spinophilin. Additional biochemical and transfected cell imaging studies showed that ␣-actinin and densin directly interact with residues 151-300 and 446 -817, respectively, of spinophilin. Taken together, we have developed a multi-antibody, shotgun proteomics approach to characterize protein interactomes in native tissues, delineating the importance of knock-out tissue controls and providing novel insights into the nature and function of the spinophilin interactome in mature striatum. Molecular & Cellular Proteomics 9:1243-1259, 2010.

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Protein Phosphatase 1γ Isoforms Linked Interactions in the Brain

et al. 2012

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Posttranslational protein modifications, in particular reversible protein phosphorylation, are important regulatory mechanisms involved in cellular signaling transduction pathways. Thousands of human proteins are phosphorylatable and the tight regulation of phosphorylation states is crucial for cell maintenance and development. Protein phosphorylation occurs primarily on serine, threonine, and tyrosine residues, through the antagonistic actions of protein kinases and phosphatases. The catalytic subunit of protein phosphatase 1 (PP1), a major Ser/Thr-phosphatase, associates with a large variety of regulatory subunits that define substrate specificity and determine specific cellular pathway responses. PP1 has been shown to bind to different proteins in the brain in order to execute key and differential functions. This work reports the identification of proteins expressed in the human brain that interact with PP1γ1 and PP1γ2 isoforms by the yeast two-hybrid method. An extensive search of PP1-binding motifs was performed for the proteins identified, revealing already known PP1 regulators but also novel interactors. Moreover, our results were integrated with the data of PP1γ interacting proteins from several public web databases, permitting the development of physical maps of the novel interactions. The PP1γ interactome thus obtained allowed for the identification of novel PP1 interacting proteins, supporting novel functions of PP1γ isoforms in the human brain.

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Association of Protein Phosphatase 1γ1 with Spinophilin Suppresses Phosphatase Activity in a Parkinson Disease Model

Cited by 31 publications

References 58 publications

PP1γ functionally augments the alternative splicing of CaMKIIδ through interaction with ASF

PP1γ functionally augments the alternative splicing of CaMKIIδ through interaction with ASF

Identification and Validation of Novel Spinophilin-associated Proteins in Rodent Striatum Using an Enhanced ex Vivo Shotgun Proteomics Approach

Protein Phosphatase 1γ Isoforms Linked Interactions in the Brain

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