Interaction of the PDZ domain of human PICK1 with class I ADP-ribosylation factors
ABSTRACT We have cloned the cDNA encoding human PICK1 (protein interacting with C kinase 1), a PDZ domain-containing protein of 415 amino acids, and also identified the Drosophila homologue by search of the databank. Northern blot analysis shows a single mRNA of about 2.0 kb ubiquitously expressed in human tissues. Although PICK1 proteins harbor a region homologous to arfaptin1 and arfaptin2, two proteins that bind to the ARF (ADP-ribosylation factor), this region of PICK1 does not interact with ARFs in the yeast two-hybrid system. On the other hand, the PDZ domain of PICK1 is capable of interacting with constitutively active, GTP-bound forms of ARF1 and ARF3, but neither with those of ARF5/6 nor with the GDP-bound ARFs. The PICK1-ARF interaction is abrogated by introduction of mutations in the PDZ domain or by deletion of the extreme C-terminus of ARF1. Thus, PICK1 specifically interacts with ARF1/3 in the GTP-bound state, suggesting that PICK1 participates in ARF1/3-mediated cellular processes.
- SourceAvailable from: Anna Antoniou
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- "To investigate the binding site between Arf1 and PICK1, we carried out co-IPs from transfected COS cells and found that a mutation in the PICK1 PDZ domain (KD27,28AA; Terashima et al., 2004) abolishes the interaction with Arf1 (Figure 2A). This is consistent with yeast two-hybrid data in a previous report, which also suggested that PICK1 interacts with the C terminus of Arf1 (Takeya et al., 2000). We show that in GST pull-down assays , deletion of the extreme C-terminal four amino acids on Arf1 (R 178 NQK 181 ) eliminates binding to PICK1 (Figure 2B). "
ABSTRACT: Inhibition of Arp2/3-mediated actin polymerization by PICK1 is a central mechanism to AMPA receptor (AMPAR) internalization and long-term depression (LTD), although the signaling pathways that modulate this process in response to NMDA receptor (NMDAR) activation are unknown. Here, we define a function for the GTPase Arf1 in this process. We show that Arf1-GTP binds PICK1 to limit PICK1-mediated inhibition of Arp2/3 activity. Expression of mutant Arf1 that does not bind PICK1 leads to reduced surface levels of GluA2-containing AMPARs and smaller spines in hippocampal neurons, which occludes subsequent NMDA-induced AMPAR internalization and spine shrinkage. In organotypic slices, NMDAR-dependent LTD of AMPAR excitatory postsynaptic currents is abolished in neurons expressing mutant Arf1. Furthermore, NMDAR stimulation downregulates Arf1 activation and binding to PICK1 via the Arf-GAP GIT1. This study defines Arf1 as a critical regulator of actin dynamics and synaptic function via modulation of PICK1.Neuron 07/2013; 79(2):293-307. DOI:10.1016/j.neuron.2013.05.003 · 15.98 Impact Factor
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- "l expression is not restricted to gangliogliomas but also present in DNETs ( Fig . 5 ) . ARF3 is a GTP - binding protein involved in protein trafficking that may modulate vesicle budding and uncoating within the Golgi apparatus ( Tsai et al . , 1991 ; Takeya et al . , 2000 ) . It is strongly up - regulated in mantle zone during brain development ( Takeya et al . , 2000 ) . ARF3 mRNA levels are lower in gangliogliomas than in controls ( Table 1 , Fig . 3 ) . This finding may relate to aberrant protein trafficking and irregular migration not only of ganglioglioma but also DNET cell components ( Fig . 5 ) . A further interesting class of molecules altered in astrocytic tumour cells as well as under epile"
ABSTRACT: Gangliogliomas, the most frequent neoplasms in patients with pharmacoresistant focal epilepsies, are characterized by histological combinations of glial and dysplastic neuronal elements, a highly differentiated phenotype and rare gene mutations. Their molecular basis and relationship to other low-grade brain tumours are not completely understood. Systematic investigations of altered gene expression in gangliogliomas have been hampered by their cellular complexity, the lack of suitable control tissue and of sensitive expression profiling approaches. Here, we have used discrete microdissected ganglioglioma and adjacent control brain tissue obtained from the neurosurgical access to the tumour of identical patients (n = 6) carefully matched for equivalent glial and neuronal elements in an amount sufficient for oligonucleotide microarray hybridization without repetitive amplification. Multivariate statistical analysis identified a rich profile of genes with altered expression in gangliogliomas. Many differentially expressed transcripts related to intra- and intercellular signalling including protein kinase C and its target NELL2 in identical ganglioglioma cell components as determined by real-time quantitative RT-PCR (qRT-PCR) and in situ hybridization. We observed the LIM-domain-binding 2 (LDB2) transcript, critical for brain development during embryogenesis, as one of the strongest reduced mRNAs in gangliogliomas. Subsequent qRT-PCR in dysembryoplastic neuroepithelial tumours (n = 7) revealed partial expression similarities as well as marked differences from gangliogliomas. The demonstrated gene expression profile differentiates gangliogliomas from other low-grade primary brain tumours. shRNA-mediated silencing of LDB2 resulted in substantially aberrant dendritic arborization in cultured developing primary hippocampal neurons. The present data characterize novel molecular mechanisms operating in gangliogliomas that contribute to the development of dysplastic neurons and an aberrant neuronal network.Brain 10/2008; 131(Pt 11):3034-50. DOI:10.1093/brain/awn233 · 10.23 Impact Factor
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- "In addition, PICK1 may reduce delivery of newly synthesized α7 nAChRs to the plasma membrane, or promote receptor internalization. The actions of PICK1 on other neurotransmitter receptors, together with the known protein interactions of PICK1 (Jin et al., 2006; Perez et al., 2001; Takeya et al., 2000), are compatible with any or even a combination of these possibilities. In a static microscopical picture, some clusters of PICK1 and α7 are adjacent and overlap partially, although precise colocalization is low (Fig. 6). "
ABSTRACT: Central to synaptic function are protein scaffolds associated with neurotransmitter receptors. Alpha7 neuronal nicotinic acetylcholine receptors (nAChRs) modulate network activity, neuronal survival and cognitive processes in the CNS, but protein scaffolds that interact with these receptors are unknown. Here we show that the PDZ-domain containing protein PICK1 binds to alpha7 nAChRs and plays a role in their clustering. PICK1 interacted with the alpha7 cytoplasmic loop in yeast in a PDZ-dependent way, and the interaction was confirmed in recombinant pull-down experiments and by co-precipitation of native proteins. Some alpha7 and PICK1 clusters were adjacent at the surface of SH-SY5Y cells and GABAergic interneurons in hippocampal cultures. Expression of PICK1 caused decreased alpha7 clustering on the surface of the interneurons in a PDZ-dependent way. These data show that PICK1 negatively regulates surface clustering of alpha7 nAChRs on hippocampal interneurons, which may be important in inhibitory functions of alpha7 in the hippocampus.Molecular and Cellular Neuroscience 07/2007; 35(2):339-55. DOI:10.1016/j.mcn.2007.03.009 · 3.73 Impact Factor