Immunohistochemical localization of PDE10A in the rat brain

Koesling

2015

Background:In striatum, cortical glutamatergic and midbrain dopaminergic inputs are integrated via cAMP. Results: PDE10A, the major cAMP-hydrolyzing enzyme in striatum, is targeted into a signaling complex containing the scaffolding proteins AKAP150, PSD95, and the NMDA receptor and released upon phosphorylation. Conclusion: Targeting of PDE10 is under control of cAMP/PKA activity. Significance: Phosphorylation-dependent release of PDE10 gives rise to a feed forward mechanism.

Section: Discussionmentioning

confidence: 99%

Phosphodiesterase 10A Is Tethered to a Synaptic Signaling Complex in Striatum

Koesling

2015

“…PDE10 has been shown to be expressed in testis and thyroid and to be particularly abundant in the putamen and caudate nucleus regions of the brain (27). Because these brain areas control major behavioral and motor functions, implying dopaminergic neurotransmission possibly involving cyclic nucleotide pathways, PDE10 as a dual specificity enzyme is currently envisaged as a potential drug target for the development of mood-affecting drugs (33). The data of a cAMP-regulated PDE10 now allow a novel look at this strategy.…”

Section: Discussionmentioning

confidence: 99%

cAMP Is a Ligand for the Tandem GAF Domain of Human Phosphodiesterase 10 and cGMP for the Tandem GAF Domain of Phosphodiesterase 11

Gross-Langenhoff

Hofbauer

Weber

et al. 2006

114

107

N-terminal tandem GAF domains are present in 5 out of 11 mammalian phosphodiesterase (PDE) families. The ligand for the GAF domains of PDEs 2, 5, and 6 is cGMP, whereas those for PDEs 10 and 11 remained enigmatic for years. Here we used the cyanobacterial cyaB1 adenylyl cyclase, which has an N-terminal tandem GAF domain closely related to those of the mammalian PDEs, as an assay system to identify the ligands for the human PDEs 10 and 11 GAF domains. We report that a chimera between the PDE10 GAF domain and the cyanobacterial cyclase was 9-fold stimulated by cAMP (EC 50 ‫؍‬ 19.8 M), whereas cGMP had only low activity. cAMP increased V max in a non-cooperative manner and did not affect the K m for ATP of 27 M. In an analogous chimeric construct with the tandem GAF domain of human PDE11A4, cGMP was identified as an allosteric activator (EC 50 ‫؍‬ 72.5 M) that increased V max of the cyclase non-cooperatively 4-fold. GAF-B of PDE10 and GAF-A of PDE11A4 contain an invariant NKFDE motif present in all mammalian PDE GAF ensembles. We mutated the aspartates within this motif in both regions and found that intramolecular signaling was considerably reduced or abolished. This was in line with all data concerning GAF domains with an NKFDE motif as far as they have been tested. The data appeared to define those GAF domains as a distinct subclass within the >3100 annotated GAF domains for which we propose a tentative classification scheme.

“…K m values of PDE10A for cAMP and cGMP are 0.26 M and 7.2 M, respectively, and V max values for them are slightly different (10). We have previously reported that PDE10A transcripts and their enzymatic activities are abundant in the striatum and testis (12), and more detailed expression patterns of PDE10A transcripts and proteins in rat brain have been recently reported (13). PDE10A is composed of at least 11 alternative splice variants possessing unique amino and carboxyl termini (10,(13)(14)(15).…”

mentioning

confidence: 93%

“…We have previously reported that PDE10A transcripts and their enzymatic activities are abundant in the striatum and testis (12), and more detailed expression patterns of PDE10A transcripts and proteins in rat brain have been recently reported (13). PDE10A is composed of at least 11 alternative splice variants possessing unique amino and carboxyl termini (10,(13)(14)(15). It is suggested that PDE10A1 and PDE10A2 transcripts are major variants in humans and that PDE10A2 and PDE10A3 transcripts are major variants in rats (Fig.…”

mentioning

confidence: 99%

Subcellular Localization of Cyclic Nucleotide Phosphodiesterase Type 10A Variants, and Alteration of the Localization by cAMP-dependent Protein Kinase-dependent Phosphorylation

Kotera

Sasaki

Tamaki

et al. 2004

Our previous studies have suggested that two phosphodiesterase type 10A (PDE10A) variants, PDE10A1 and PDE10A2 transcripts, are mainly expressed in humans and that PDE10A2 and PDE10A3 transcripts are major variants in rats. In the present study, immunoblot analysis demonstrated that PDE10A proteins, especially PDE10A2, are more abundant in membrane fractions than in cytosolic fractions of rat striatum. Recombinant PDE10A1 and PDE10A3 were produced only in cytosolic fractions of transfected PC12h cells. By contrast, recombinant PDE10A2 was present mainly in membrane fractions. This finding agreed well with the result of subcellular fractionation of PDE10A in rat striatum. Immunocytochemical analysis showed that PDE10A2 was localized in the Golgi apparatus of transfected PC12h cells. PDE10A2 was phosphorylated by cAMP-dependent protein kinase (PKA) at Thr 16 . Interestingly, recombinant protein of wild-type PDE10A2, but not PDE10A2 mutant with an Ala replacement at Thr 16 , was distributed to cytosolic fractions by co-transfection with a plasmid encoding the catalytic subunit of PKA. A PDE10A2 mutant with Glu substitution at Thr 16 , which can be a mimic of phosphorylation, was localized in the cytosolic fractions of transfected PC12h cells. These observations implied that phosphorylation of PDE10A2 at Thr 16 by PKA caused alteration of subcellular localization of PDE10A2 from the Golgi apparatus to cytosol. It is hypothesized that cAMP signaling in the Golgi area and the cytosol in neurons is controlled through alteration of subcellular localization of PDE10A brought by activation of PKA in response to intracellular elevations of cAMP.Cyclic nucleotides, cAMP and cGMP, control physiological functions in neuronal networks. Dopamine, adenosine, and vasoactive intestinal peptide are neuronal transmitters and cause elevation of intracellular cAMP levels in striatal neurons (1-3). Cyclic AMP-dependent protein kinase (PKA), 1 which is activated by cAMP, phosphorylates certain receptors and intracellular proteins such as dopamine-and cAMP-related phosphoprotein of M r 32,000 (1) and glutamate receptor (4, 5) in striatal neurons. The cellular compartmentalization of cAMP signaling through association with several forms of protein kinase A-anchoring proteins (AKAPs), which interact with the regulatory subunit of PKA, has been discussed (6). Disorder of subcellular localization of PKA and AKAP prevents appropriate differentiation of PC12 cells stimulated by cAMP-producing agents (7). Thus, signal transduction by cyclic nucleotides is regulated by multiple components in neurons.Cyclic nucleotides are hydrolyzed by phosphodiesterases (PDEs), which consist of 11 families (8, 9). We have isolated cDNAs for a dual substrate PDE that hydrolyzes both cAMP and cGMP (PDE10A) from humans and rats (10), and another group has reported mouse PDE10A cDNA (11). K m values of PDE10A for cAMP and cGMP are 0.26 M and 7.2 M, respectively, and V max values for them are slightly different (10). We have previously reported that PDE10A transcrip...