TTLL1 and TTLL4 polyglutamylases are required for the neurodegenerative phenotypes in pcd mice.

Polyglutamylation is a dynamic posttranslational modification where glutamate residues are added to substrate proteins by 8 tubulin tyrosine ligase-like (TTLL) family members (writers) and removed by the 6 member Nna1/CCP family of carboxypeptidases (erasers). Genetic disruption of polyglutamylation leading to hyperglutamylation causes neurodegenerative phenotypes in humans and animal models; the best characterized being the Purkinje cell degeneration (pcd) mouse, a mutant of the gene encoding Nna1/CCP1, the prototypic eraser. Emphasizing the functional importance of the balance between glutamate addition and elimination, loss of TTLL1 prevents Purkinje cell degeneration in pcd.

Interactional misalignment in the UK NHS 111 healthcare telephone triage service.

Background: A recent review of primary care serious incidents suggests that diagnosis and assessment problems, underpinned by communication failures, involving the UK telephone triage service, NHS 111, may contribute to patient harm.

Methods: The present study utilised conversation analysis to address the lack of evaluative research examining the NHS 111 system and in particular interactions between system components (call handler, computerized decision support system, patients/caller).

Results: Analysis of audio recorded call interactions revealed interactional misalignment across four mapped call phases (eliciting caller details, establishing reason for call, completing the Pathways assessment, and agreeing the outcome).

Glycosylation of Cblns attenuates their receptor binding.

Cbln1 is the prototype of a family (Cbln1-Cbln4) of secreted glycoproteins and is essential for normal synapse structure and function in cerebellum by bridging presynaptic Nrxn to postsynaptic Grid2. Here we report the effects of glycosylation on the in vitro receptor binding properties of Cblns. Cbln1, 2 and 4 harbor two N-linked glycosylation sites, one at the N-terminus is in a region implicated in Nrxn binding and the second is in the C1q domain, a region involved in Grid2 binding.

Role of Cytosolic Carboxypeptidase 5 in Neuronal Survival and Spermatogenesis.

Proteins may undergo a type of posttranslational modification - polyglutamylation, where a glutamate residue is enzymatically linked to the γ-carboxyl group of a glutamate in the primary sequence of proteins and additional glutamates are then sequentially added via α-carboxyl-linkages to the growing glutamate side chain. Nna1 (a.k.

Evidence that brief self-affirming implementation intentions can reduce work-related anxiety in downsize survivors.

Background And Objectives: Workers were recruited from a UK further education college during a period of organizational downsizing. This study assessed the effects of a brief health psychology intervention on work-related stress in downsize survivors.

Design And Methods: Sixty-six employees were randomly allocated to one of two conditions: one in which they were asked to create a work-related self-affirming implementation intention (WS-AII) or a control.

Comparison of the enzymatic and functional properties of three cytosolic carboxypeptidase family members.

Nna1 (CCP1) defines a subfamily of M14 metallocarboxypeptidases (CCP1-6) and is mutated in pcd (Purkinje cell degeneration) mice. Nna1, CCP4, and CCP6 are involved in the post-translational process of polyglutamylation, where they catalyze the removal of polyglutamate side chains. However, it is unknown whether these three cytosolic carboxypeptidases share identical enzymatic properties and redundant biological functions.

A structural and functional analysis of Nna1 in Purkinje cell degeneration (pcd) mice.

The axotomy-inducible enzyme Nna1 defines a subfamily of M14 metallocarboxypeptidases, and its mutation underlies the Purkinje cell degeneration (pcd) mouse. However, the relationship among its catalytic activity, substrate specificities, and the critical processes of neurodegeneration/axon regeneration is incompletely understood. Here we used a transgenic rescue strategy targeting expression of modified forms of Nna1 to Purkinje cells in pcd mice to determine structure-activity relationships for neuronal survival and in parallel characterized the enzymatic properties of purified recombinant Nna1.

Direct and indirect effects of mood on risk decision making in safety-critical workers.

The study aimed to examine the direct influence of specific moods (fatigue, anxiety, happiness) on risk in safety-critical decision making. It further aimed to explore indirect effects, specifically, the potential mediating effects of information processing assessed using a goodness-of-simulation task. Trait fatigue and anxiety were associated with an increase in risk taking on the Safety-Critical Personal Risk Inventory (S-CPRI), however the effect of fatigue was partialled out by anxiety.

Pcp4l1 contains an auto-inhibitory element that prevents its IQ motif from binding to calmodulin.

Purkinje cell protein 4-like 1 (Pcp4l1) is a small neuronal IQ motif protein closely related to the calmodulin-binding protein Pcp4/PEP-19. PEP-19 interacts with calmodulin via its IQ motif to inhibit calmodulin-dependent enzymes and we hypothesized Pcp4l1 would have similar properties. Surprisingly, full-length Pcp4l1 does not interact with calmodulin in yeast two-hybrid or pulldown experiments yet a synthetic peptide constituting only the IQ motif of Pcp4l1 binds calmodulin and inhibits calmodulin-dependent kinase II.

The Cbln family of proteins interact with multiple signaling pathways.

Cerebellin precursor protein (Cbln1) is essential for synapse integrity in cerebellum through assembly into complexes that bridge pre-synaptic β-neurexins (Nrxn) to post-synaptic GluRδ2. However, GluRδ2 is largely cerebellum-specific, yet Cbln1 and its little studied family members, Cbln2 and Cbln4, are expressed throughout brain. Therefore, we investigated whether additional proteins mediate Cbln family actions.

Comparison of Cbln1 and Cbln2 functions using transgenic and knockout mice.

Cerebellin precursor protein 1 (Cbln1) is the prototype of a family of secreted neuronal glycoproteins (Cbln1-4) and its genetic elimination results in synaptic alterations in cerebellum (CB) and striatum. In CB, Cbln1 acts as a bi-functional ligand bridging pre-synaptic β-neurexins on granule cells to post-synaptic Grid2 on Purkinje neurons. Although much is known concerning the action of Cbln1, little is known of the function of its other family members.

Impaired locomotor learning and altered cerebellar synaptic plasticity in pep-19/PCP4-null mice.

PEP-19/PCP4 maps within the Down syndrome critical region and encodes a small, predominantly neuronal, IQ motif protein. Pep-19 binds calmodulin and inhibits calmodulin-dependent signaling, which is critical for synaptic function, and therefore alterations in Pep-19 levels may affect synaptic plasticity and behavior. To investigate its possible role, we generated and characterized pep-19/pcp4-null mice.

Is the loss of thalamostriatal neurons protective in parkinsonism?

Neuronal loss in Parkinson's disease (PD) is more widespread than originally thought. Among the extrastriatal sites in which significant loss of neurons has been reported is the centremedian-parafascicular (CM-PF) complex of the thalamus, which provides one of the three major afferent sources to the striatum. The functional significance of CM-PF loss in PD is unclear.

Characterization of trans-neuronal trafficking of Cbln1.

Cbln1, a glycoprotein secreted from granule cells and GluRdelta2 in the postsynaptic densities of Purkinje cells are components of an incompletely understood pathway essential for integrity and plasticity of parallel fiber-Purkinje cell synapses. We show that Cbln1 undergoes anterograde transport from granule cells to Purkinje cells and Bergmann glia, and enters the endolysosomal trafficking system, raising the possibility that Cbln1 exerts its activity on or within Purkinje cells and Bergmann glia. Cbln1 is absent in Purkinje cells and Bergmann glia of GluRdelta2-null mice, suggesting a mechanistic convergence on Cbln1 trafficking.

Cbln1 accumulates and colocalizes with Cbln3 and GluRdelta2 at parallel fiber-Purkinje cell synapses in the mouse cerebellum.

Cbln1 (a.k.a.

Sensorimotor enhancement in mouse mutants lacking the Purkinje cell-specific Gi/o modulator, Pcp2(L7).

Pcp2(L7) is a GoLoco domain protein specifically and abundantly expressed in cerebellar Purkinje cells. It has been hypothesized to "tune" G(i/o)-coupled receptor modulation of physiological effectors, including the P-type Ca(2+) channel. We have analyzed a mouse mutant in which the Pcp2(L7) gene was inactivated and find significant anatomical, behavioral and electrophysiological changes.

Mapping of Cbln1-like immunoreactivity in adult and developing mouse brain and its localization to the endolysosomal compartment of neurons.

Cbln1 is a secreted glycoprotein essential for synapse structure and function in cerebellum that is also expressed in extracerebellar structures where its function is unknown. Furthermore, Cbln1 assembles into homomeric complexes and heteromeric complexes with three family members (Cbln2-Cbln4), thereby influencing each other's degradation and secretion. Therefore, to understand its function, it is essential to establish the location of Cbln1 relative to other family members.

Cbln1 is essential for interaction-dependent secretion of Cbln3.

Cbln1 and the orphan glutamate receptor GluRdelta2 are pre- and postsynaptic components, respectively, of a novel transneuronal signaling pathway regulating synapse structure and function. We show here that Cbln1 is secreted from cerebellar granule cells in complex with a related protein, Cbln3. However, cbln1- and cbln3-null mice have different phenotypes and cbln1 cbln3 double-null mice have deficits identical to those of cbln1 knockout mice.

The carboxypeptidase-like substrate-binding site in Nna1 is essential for the rescue of the Purkinje cell degeneration (pcd) phenotype.

The Purkinje cell degeneration (pcd) phenotype is characterized by adult onset neurodegeneration resulting from mutations in Nna1, a gene encoding an intracellular protein with a putative metallocarboxypeptidase domain. As Nna1 is also induced in axotomized motor neurons, the elucidation of its function can shed light on previously unsuspected mechanisms common to degenerative and regenerative responses. Structural modeling revealed that Nna1 and three related gene products constitute a new subfamily of metallocarboxypeptidases with a distinctive substrate-binding site.

The Purkinje cell degeneration (pcd) mouse: an unexpected molecular link between neuronal degeneration and regeneration.

The spontaneous autosomal recessive mouse mutation, Purkinje cell degeneration (pcd), was first identified through its ataxic behavior. Since its discovery in the 1970s, the strain has undergone extensive investigation, although another quarter century elapsed until the mutant gene (agtpbp1 a.k.

The influence of phosphorylation on the activity and structure of the neuronal IQ motif protein, PEP-19.

PEP-19 is a 7.6 kDa neuronally expressed polypeptide that contains a single calmodulin-binding IQ motif. The calmodulin-binding activity of several neuronal IQ motif proteins is regulated by phosphorylation of a conserved serine.

Cbln1 is essential for synaptic integrity and plasticity in the cerebellum.

Cbln1 is a cerebellum-specific protein of previously unknown function that is structurally related to the C1q and tumor necrosis factor families of proteins. We show that Cbln1 is a glycoprotein secreted from cerebellar granule cells that is essential for three processes in cerebellar Purkinje cells: the matching and maintenance of pre- and postsynaptic elements at parallel fiber-Purkinje cell synapses, the establishment of the proper pattern of climbing fiber-Purkinje cell innervation, and induction of long-term depression at parallel fiber-Purkinje cell synapses. Notably, the phenotype of cbln1-null mice mimics loss-of-function mutations in the orphan glutamate receptor, GluR delta2, a gene selectively expressed in Purkinje neurons.

The structure and proteolytic processing of Cbln1 complexes.

The hexadecapeptide cerebellin is present in the brains of many vertebrate species and is derived from a larger protein, Cbln1 (cerebellin 1 precursor protein). Although cerebellin has features of a neuropeptide, Cbln1 belongs to the C1q/tumor necrosis factor superfamily of secreted proteins, suggesting that it is the biologically active molecule and the proteolytic events that generate cerebellin serve another function. Therefore, we assessed whether Cbln1 undergoes proteolytic processing and determined what consequences the cleavage events necessary to produce cerebellin have on the structure of Cbln1.

Expression of Bcl-2 extends the survival of olfactory receptor neurons in the absence of an olfactory bulb.

In the olfactory neuroepithelium, the number of olfactory receptor neurons (ORNs) is maintained at a relatively constant level by a precise balance between the elimination of mature receptors and proliferation of their precursors. However, little is known of the mechanisms that couple alterations in receptor death rates to changes in precursor proliferation. To investigate this relationship, we generated a line of mice expressing Bcl-2, a protein with anti-apoptotic properties, in mature olfactory receptor neurons using the Olfactory Marker Protein (OMP) promoter.

Identification of candidate Purkinje cell-specific markers by gene expression profiling in wild-type and pcd(3J) mice.

The identification of mRNAs that have restricted expression patterns in the brain represents powerful tools with which to characterize and manipulate the nervous system. Here, we describe a strategy using microarray technology (Affymetrix Mouse Genome 430 2.0 Arrays) to identify mRNA transcripts that are candidate markers of cerebellar Purkinje neurons.