Characterization of Cln3p, the gene product responsible for juvenile neuronal ceroid lipofuscinosis, as a lysosomal integral membrane glycoprotein

Ezaki, Junji; Takeda-Ezaki, Mitsue; Koike, Masato; Ohsawa, Yoshiyuki; Taka, Hikari; Mineki, Reiko; Murayama, Kimie; Uchiyama, Yasuo; Ueno, Takashi; Kominami, Eiki

doi:10.1046/j.1471-4159.2003.02132.x

Cited by 66 publications

(66 citation statements)

References 52 publications

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“…In non-neuronal cells, CLN3 localizes primarily to endosomes and lysosomes (Haskell et al, 2000;Ezaki et al, 2003;Mao et al, 2003;Kyttala et al, 2004), whereas in neurons, CLN3 is also detected in vesicular structures at synapses and along neurites (Haskell et al, 2000;Luiro et al, 2001;Kyttala et al, 2004). These findings suggest that in most/all cell types, CLN3 performs a basic function related to the lysosome, whereas in neurons, CLN3 may take on additional specialized tasks.…”

Section: Introductionmentioning

confidence: 94%

“…In adult murine brain, immunostaining and/or in situ hybridization for transcript localizes CLN3 to neurons in the cortex, hippocampus, cerebellum, thalamus, and hypothalamus (Luiro et al, 2001;Cotman et al, 2002). Immunoblot of lysates from murine tissues shows abundant CLN3 in liver, kidney, and spleen and low amounts in pancreas and brain (Ezaki et al, 2003). A study on human tissues showed low CLN3 levels in the liver but high levels in brain by immunoblot of tissue lysates (Margraf et al, 1999).…”

Section: Introductionmentioning

confidence: 98%

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A Knock-In Reporter Model of Batten Disease

Eliason¹,

Stein²,

Mao³

et al. 2007

J. Neurosci.

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Juvenile neuronal ceroid lipofuscinosis is a severe inherited neurodegenerative disease resulting from mutations in CLN3 (ceroidlipofuscinosis, neuronal 3, juvenile). CLN3 function, and where and when it is expressed during development, is not known. In this study, we generated a knock-in reporter mouse to elucidate CLN3 expression during embryogenesis and after birth and to correlate expression and behavior in a CLN3-deficient mouse. In embryonic brain, expression appeared in the cortical plate. In postnatal brain, expression was prominent in the cortex, subiculum, parasubiculum, granule neurons of the dentate gyrus, and some brainstem nuclei. In adult brain, reporter gene expression waned in most areas but remained in vascular endothelia and the dentate gyrus. Mice homozygous for Cln3 deletion showed two hallmark pathological features of the neuronal ceroid lipofuscinosises: autofluorescent inclusions and lysosomal enzyme elevation. Moreover, CLN3-deficient reporter mice displayed progressive neurological deficits, including impaired motor function, decreased overall activity, acquisition of resting tremors, and increased susceptibility to pentilentetrazole-induced seizures. Notably, seizure induction in heterozygous mice was accompanied by enhanced reporter expression. This model provides us with the unique ability to correlate expression with pathology and behavior, thus facilitating the elucidation of CLN3 function and the pathogenesis of Batten disease.

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Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 98%

A Knock-In Reporter Model of Batten Disease

Eliason¹,

Stein²,

Mao³

et al. 2007

J. Neurosci.

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“…To first determine whether the CLN3-encoded protein, battenin, was present in the different AV fractions, which might suggest a direct role for battenin in the autophagic pathway, we probed immunoblots of wild-type (Cln3 ϩ/ϩ ) and homozygous Cln3 ⌬ex7/8 fractions using a previously characterized anti-battenin antibody (23). On wild-type immunoblots, we observed a faint ϳ60 -65-kDa smear (asterisk in Fig.…”

Section: Battenin Is Highly Enriched In Purified Autophagic Vacuoles-mentioning

confidence: 99%

Autophagy Is Disrupted in a Knock-in Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis

Cao

Espinola

Fossale

et al. 2006

Journal of Biological Chemistry

232

222

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Juvenile neuronal ceroid lipofuscinosis is caused by mutation of a novel, endosomal/lysosomal membrane protein encoded by CLN3. The observation that the mitochondrial ATPase subunit c protein accumulates in this disease suggests that autophagy, a pathway that regulates mitochondrial turnover, may be disrupted. To test this hypothesis, we examined the autophagic pathway in Cln3 ⌬ex7/8 knock-in mice and CbCln3 ⌬ex7/8 cerebellar cells, accurate genetic models of juvenile neuronal ceroid lipofuscinosis. In homozygous knock-in mice, we found that the autophagy marker LC3-II was increased, and mammalian target of rapamycin was down-regulated. Moreover, isolated autophagic vacuoles and lysosomes from homozygous knock-in mice were less mature in their ultrastructural morphology than the wild-type organelles, and subunit c accumulated in autophagic vacuoles. Intriguingly, we also observed subunit c accumulation in autophagic vacuoles in normal aging mice. Upon further investigation of the autophagic pathway in homozygous knock-in cerebellar cells, we found that LC3-positive vesicles were altered and overlap of endocytic and lysosomal dyes was reduced when autophagy was stimulated, compared with wildtype cells. Surprisingly, however, stimulation of autophagy did not significantly impact cell survival, but inhibition of autophagy led to cell death. Together these observations suggest that autophagy is disrupted in juvenile neuronal ceroid lipofuscinosis, likely at the level of autophagic vacuolar maturation, and that activation of autophagy may be a prosurvival feedback response in the disease process.Macroautophagy (herein referred to as autophagy) is a nonselective process by which cytoplasmic constituents are turned over (reviewed in Refs. 1 and 2). Elegant work in yeast has led to the genetic dissection of many of the proteins involved in this pathway (3, 4), which are mostly conserved in mammals (5, 6).The pathway is initiated at times of stress or nutritional deprivation to generate metabolites for cellular survival, but autophagy is also responsible for normal housekeeping. Although the regulatory control of autophagy remains to be fully elucidated, the general process from engulfment to degradation has been delineated (2). Initiation of the pathway involves de novo formation of an isolation membrane that expands to engulf cytoplasmic constituents, including organelles, and encloses to form a double membrane autophagic vacuole. This formed autophagic vacuole is then increasingly acidified, and proteases are delivered through fusion with late endosomes and lysosomes. The inner membrane is degraded to form a single membrane autolysosome, where constituents are finally completely degraded for recycling of metabolites to the cell.Autophagy is emerging as a major pathway involved in a number of neurodegenerative diseases, including Parkinson disease (7, 8), Huntington disease (9 -11), and Alzheimer disease (12, 13). In each case, autophagic vacuoles accumulate, suggesting that activation of autophagy is a common feature ...

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“…PPT1 and TPP1 are both proteins with known lysosomal functions. Battenin, the gene product of CLN3, although its function is unknown, has been demonstrated to localize to the lysosomal membrane (Ezaki et al 2003).…”

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confidence: 99%

Palmitoyl-Protein Thioesterase 1 Deficiency in Drosophila melanogaster Causes Accumulation of Abnormal Storage Material and Reduced Life Span

et al. 2006

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Human neuronal ceroid lipofuscinoses (NCLs) are a group of genetic neurodegenerative diseases characterized by progressive death of neurons in the central nervous system (CNS) and accumulation of abnormal lysosomal storage material. Infantile NCL (INCL), the most severe form of NCL, is caused by mutations in the Ppt1 gene, which encodes the lysosomal enzyme palmitoyl-protein thioesterase 1 (Ppt1). We generated mutations in the Ppt1 ortholog of Drosophila melanogaster to characterize phenotypes caused by Ppt1 deficiency in flies. Ppt1-deficient flies accumulate abnormal autofluorescent storage material predominantly in the adult CNS and have a life span 30% shorter than wild type, phenotypes that generally recapitulate disease-associated phenotypes common to all forms of NCL. In contrast, some phenotypes of Ppt1-deficient flies differed from those observed in human INCL. Storage material in flies appeared as highly laminar spherical deposits in cells of the brain and as curvilinear profiles in cells of the thoracic ganglion. This contrasts with the granular deposits characteristic of human INCL. In addition, the reduced life span of Ppt1-deficient flies is not caused by progressive death of CNS neurons. No changes in brain morphology or increases in apoptotic cell death of CNS neurons were detected in Ppt1-deficient flies, even at advanced ages. Thus, Ppt1-deficient flies accumulate abnormal storage material and have a shortened life span without evidence of concomitant neurodegeneration.

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Characterization of Cln3p, the gene product responsible for juvenile neuronal ceroid lipofuscinosis, as a lysosomal integral membrane glycoprotein

Cited by 66 publications

References 52 publications

A Knock-In Reporter Model of Batten Disease

A Knock-In Reporter Model of Batten Disease

Autophagy Is Disrupted in a Knock-in Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis

Palmitoyl-Protein Thioesterase 1 Deficiency in Drosophila melanogaster Causes Accumulation of Abnormal Storage Material and Reduced Life Span

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