Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CLN3”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2001

High resolution MRI reveals global changes in brains of Cln3 mutant mice.

Batten disease, the juvenile-onset form of neuronal ceroid lipofuscinosis (NCL), is a progressive neurodegenerative disorder of childhood with an age of onset of 5-10 years of age. JNCL is caused by mutations in the CLN3 gene which encodes a membrane protein of unknown function. Magnetic resonance imaging of the brain of juvenile NCL patients has revealed changes in signal intensity and tissue atrophy, predominantly in the cortex and cerebellum. A mouse model for Batten disease was created by targeted disruption of the murine Cln3 gene in order to further understanding of the pathophysiology of Batten disease and to evaluate potential therapeutic approaches. Several features of the disease are displayed by Cln3 mice including accumulation of characteristic storage material in neurons. The aim of this work was to investigate neurodegeneration in the Cln3 mouse model using high resolution magnetic resonance imaging to measure signal intensity ratios in selected regions of interest. Global changes were observed in the brains of 12-month-old mutant mice that mirror those seen in juvenile NCL patients. There is a decrease in signal intensity ratio in grey matter regions including cortex, hippocampus and cerebellum, tissues where neuronal storage accumulation and cell loss have been seen in the mouse model. The alterations seen in Cln3 mutant mice support the validity of further imaging studies and suggest that this method will have application in assessment of therapeutic approaches in the study of mutant mouse models of NCL including the Cln3 mouse.

Animals↗
PubMed2003

Two motifs target Batten disease protein CLN3 to lysosomes in transfected nonneuronal and neuronal cells.

Batten disease is a neurodegenerative disorder resulting from mutations in CLN3, a polytopic membrane protein, whose predominant intracellular destination in nonneuronal cells is the lysosome. The topology of CLN3 protein, its lysosomal targeting mechanism, and the development of Batten disease are poorly understood. We provide experimental evidence that both the N and C termini and one large loop domain of CLN3 face the cytoplasm. We have identified two lysosomal targeting motifs that mediate the sorting of CLN3 in transfected nonneuronal and neuronal cells: an unconventional motif in the long C-terminal cytosolic tail consisting of a methionine and a glycine separated by nine amino acids [M(X)9G], and a more conventional dileucine motif, located in the large cytosolic loop domain and preceded by an acidic patch. Each motif on its own was sufficient to mediate lysosomal targeting, but optimal efficiency required both. Interestingly, in primary neurons, CLN3 was prominently seen both in lysosomes in the cell body and in endosomes, containing early endosomal antigen-1 along neuronal processes. Because there are few lysosomes in axons and peripheral parts of dendrites, the presence of CLN3 in endosomes of neurons may be functionally important. Endosomal association of the protein was independent of the two lysosomal targeting motifs.

Amino Acid Motifs↗
PubMed2002

Motifs within the CLN3 protein: modulation of cell growth rates and apoptosis.

Juvenile Batten disease (JNCL) is an autosomal recessive disease that results from mutations in the CLN3 gene. The wild-type CLN3 gene coding sequence has 15 exons, and the translated protein consists of 438 amino acids. The most commonly observed mutation is a 1.02 kb deletion in the genomic DNA. This deletion results in a truncated protein due to the loss of amino acids 154-438, and the introduction of 28 novel amino acids at the c-terminus. We demonstrate that, compared to normal controls, CLN3-deficient immortalization of lymphoblasts homozygous for this deletion grow at a slower rate, and show increased sensitivity to etoposide-induced apoptosis, supporting the notion that CLN3 may negatively regulate apoptosis. Using immortalized JNCL lymphoblast cell lines as a model system, we assess the effects of specific CLN3 mutations on cell growth rates and protection from etoposide-induced apoptosis. Protection from etoposide-induced apoptosis occurs and the cell growth rate is restored following transfection of JNCL lymphoblasts with mutant CLN3 cDNA that includes exons 11 or 13. We show that deletion of the glycosylation sites 71NQSH74 and 310NTSL313, and also mutations within the highly conserved amino acid stretches 184WSSGTGGAGLLG195, 291VYFAE295 and 330VFASRSSL337, result in slowed growth and susceptibility to apoptosis.

Amino Acid Motifs↗
PubMed1998

Transcriptional regulation of CLN3 expression by glucose in Saccharomyces cerevisiae.

In Saccharomyces cerevisiae, the transition from the G1 phase of the mitotic cycle into S phase is controlled by a set of G1 cyclins that regulate the activity of the protein kinase encoded by CDC28. Yeast cells regulate progress through the G1/S boundary in response to nutrients, moving quickly through G1 in glucose medium and more slowly in poorer medium. We have examined connections between glucose and the level of the message encoding Cln3, a G1 cyclin. We found that glucose positively regulates CLN3 mRNA levels through a set of repeated AAGAAAAA (A2GA5) elements within the CLN3 promoter. Mutations in these sequences reduce both transcriptional activation and specific interaction between CLN3 promoter elements and proteins in yeast extracts. Creation of five point mutations, replacing the G's within these repeats with T's, in the CLN3 promoter substantially reduces CLN3 expression in glucose medium and inhibits the ability of the cells to maintain a constant size when shifted into glucose.

Base Sequence↗
PubMed2001

Early cell cycle box-mediated transcription of CLN3 and SWI4 contributes to the proper timing of the G(1)-to-S transition in budding yeast.

The Cln3-Cdc28 kinase is required to activate the Swi4-Swi6 transcription complex which induces CLN1 and CLN2 transcription in late G(1) and drives the transition to S. Cln3 and Swi4 are both rate limiting for G(1) progression, and they are coordinately transcribed to peak at the M/G(1) boundary. Early cell cycle box (ECB) elements, which confer M/G(1)-specific transcription, have been found in both promoters, and elimination of all ECB elements from the CLN3 promoter causes both a loss of periodicity and Cln3-deficient phenotypes, which include an extended G(1) interval and increased cell volume. Mutants lacking the ECB elements in both the CLN3 and SWI4 promoters have low and deregulated levels of CLN transcripts, and the G(1)-to-S transition for these mutants is delayed and highly variable. These observations support the view that the coordinated rise of Cln3 and Swi4 levels mediated by ECB-dependent transcription controls the timing of the G(1)-to-S phase transition.

Blotting, Northern↗
PubMed2004

[The role of Cln3 in filamentous growth and invasive growth of Saccharomyces cerevisiae].

Cln3 is one of G1 cyclins in Saccharomyces cerevisiae. In order to study the function of Cln3 in cell cycle and morphogenesis, we constructed a cln3 null mutant and analyzed its phenotype. Our results indicated that the cln3 null mutant was more sensitive to alpha pheromone, and arrested at G1 phase. The hypersensitivity to alpha-pheromone was not suppressed by overexpression of SGV1. The null mutant showed a different phenotype with that of the other two G1 cyclin mutants. The filamentous growth in diploid cells of cln3 mutant was stronger than that in wild type cells, while invasive growth of the haploid cells was partially inhibited. The results suggested that the Cln3 plays a unique function in morphogenesis under a different mechanism with that used by Cln1 and Cln2.

Cyclin-Dependent Kinases↗
PubMed1994

Genetic mapping of the Batten disease locus (CLN3) to the interval D16S288-D16S383 by analysis of haplotypes and allelic association.

CLN3, the gene for juvenile-onset neuronal ceroid lipofuscinosis (JNCL) or Batten disease, has been localized by genetic linkage analysis to chromosome 16p between loci D16S297 and D16S57. We have now further refined the localization of CLN3 by haplotype analysis using two new microsatellite markers from loci D16S383 and SPN in the D16S297-D16S57 interval on a larger collaborative family resource consisting of 142 JNCL pedigrees. Crossover events in 3 maternal meioses define new flanking markers for CLN3 and localize the gene to the interval at 16p12.1-p11.2 between D16S288 and D16S383, which corresponds to a genetic distance of 2.1 cM. Within this interval 4 microsatellite loci are in strong linkage disequilibrium with CLN3, and extended haplotype analysis of the associated alleles indicates that CLN3 is in closest proximity to loci D16S299 and D16S298.

Alleles↗
PubMed2001

Mouse gene knockout models for the CLN2 and CLN3 forms of ceroid lipofuscinosis.

The childhood neuronal ceroid-lipofuscinoses (NCLs) are autosomal-recessively inherited neurodegenerative disorders that result in severe cognitive decline and premature death. The genetic bases for a number of different forms of NCL, including those designated CLN2 and CLN3, have now been determined. However, the mechanisms by which the gene defects cause the disease pathology are not known and no effective treatments for these disorders have been developed. To provide tools for studying the mechanisms underlying the disease pathologies and for screening potential therapeutic interventions, work is under way to develop mouse models for the CLN2 and CLN3 disorders. Targeted gene replacement was used to generate mice in which the murine orthologue of the CLN3 gene has been knocked out. Mice that are homozygous for the Cln3 knockout allele develop a number of pathological features similar to those that occur in the human disorder. Among these are accumulation of autofluorescent lysosomal storage bodies, behavioural abnormalities, retinal degeneration, and premature death. On a mixed strain genetic background, the appearance of these symptoms was quite variable, suggesting that other genes can modify the effects of CLN3 mutations. Work to develop a similar mouse gene knockout model for the CLN2 disorder is well under way. Chimaeric mice have been developed with cells that carry an induced mutation in the mouse orthologue of the CLN2 gene that would prevent synthesis of a functional CLN2 protein in mice that are homozygous for the mutation. Mice will be developed that are homozygous for this mutation, and these animals will be evaluated for the development of pathologies similar to those that occur in the human disorder.

Aminopeptidases↗
PubMed2001

Caenorhabditis elegans homologues of the CLN3 gene, mutated in juvenile neuronal ceroid lipofuscinosis.

Neuronal ceroid lipofuscinoses (NCLs) are the most common hereditary neurodegenerative disorders of childhood. The first symptom of this heterogeneous group of devastating lysosomal storage diseases is progressive visual failure. The different forms of NCL can be distinguished by age of onset, clinical features and the characteristics of the accumulated materials. The juvenile form, Batten-Spielmeyer-Vogt disease which is caused by mutations in the CLN3 gene, is the most frequent form of the disease in which loss of vision becomes apparent around the age of 5-8 years. The gene was found to encode a novel integral membrane protein localizing to the lysosomes, confirming that the primary defect in NCL is in lysosomal function. The CLN3 protein function is still unknown, and is examined in several model organisms. We are studying the nematode Caenorhabditis elegans, and have identified three CLN3 homologues. In order to investigate the role of the CLN3 protein in C. elegans, Cecln-3 deletion mutants are being isolated from an ethyl methanesulphonate (EMS)-induced deletion mutant library. Examination of these mutants may provide us with information that will help in dissecting the processes in which the CLN3 protein is involved. In this library two mutated C. elegans Cln-3 loci have been identified, of which one mutant, NL748, was isolated. This mutant contains a deletion of the whole gene. The deletion mutant was characterized with regard to life expectancy, and showed no significant differences when compared with wild-type.

Animals↗
PubMed2004

CLN3L, a novel protein related to the Batten disease protein, is overexpressed in Cln3-/- mice and in Batten disease.

Batten disease is a severe autosomal recessive neurodegenerative disease which results from mutations in CLN3. Although the gene was cloned in 1995, the tissue distribution and subcellular localization of the CLN3 protein (CLN3P) remains inconclusive. We have demonstrated the presence of a novel 33 kDa protein in both normal human and wild-type mouse brain. This 33 kDa protein, which is overexpressed in brains of patients with Batten disease and in Cln3-/- mouse brain, binds to the antibody raised against the peptide sequence of CLN3P and results in aberrant CLN3P localization studies. We expressed a novel 33 kDa protein that is highly similar to CLN3P. We showed that the 33 kDa protein is identical to that recognized in Batten disease and Cln3-/- brain. These studies strongly suggest the presence of an alternative CLN3-like (CLN3L) product in Batten disease. Previous studies of CLN3P tissue distribution and intracellular localization will require extensive reanalysis in order to determine the true expression of CLN3P.

Amino Acid Sequence↗
PubMed1999

Genetic analysis of the shared role of CLN3 and BCK2 at the G(1)-S transition in Saccharomyces cerevisiae.

The transcription complexes SBF and MBF mediate the G(1)-S transition in the cell cycle of Saccharomyces cerevisiae. In late G(1), SBF and MBF induce a burst of transcription in a number of genes, including G(1)- and S-phase cyclins. Activation of SBF and MBF depends on the G(1) cyclin Cln3 and a largely uncharacterized protein called Bck2. We show here that the induction of SBF/MBF target genes by Bck2 depends partly, but not wholly, on SBF and MBF. Unlike Cln3, Bck2 is capable of inducing its transcriptional targets in the absence of functional Cdc28. Our results revealed promoter-specific mechanisms of regulation by Cln3, Bck2, SBF, and MBF. We isolated high-copy suppressors of the cln3 bck2 growth defect; all of these had the ability to increase CLN2 expression. One of these suppressors was the negative regulator of meiosis RME1. Rme1 induces CLN2, and we show that it has a haploid-specific role in regulating cell size and pheromone sensitivity. Genetic analysis of the cln3 bck2 defect showed that CLN1, CLN2, and other SBF/MBF target genes have an essential role in addition to the degradation of Sic1.

Cell Cycle↗
PubMed1998

Biosynthesis and intracellular targeting of the CLN3 protein defective in Batten disease.

Batten disease (juvenile-onset neuronal ceroid lipofuscinosis, JNCL), the most common neurodegenerative disorder of childhood, is caused by mutations in a recently identified gene ( CLN3 ) localized to chromosome 16p11.2-12.1. To elucidate the biosynthesis and localization of the CLN3 protein, we expressed CLN3 cDNA in COS-1 and HeLa cell lines. In vitro translation, immunoprecipitation and Western blotting analyses detected an approximately 43 kDa polypeptide. Pulse-chase experiments indicated that the CLN3 protein is synthesized as an N -glycosylated single-chain polypeptide, which was not detected in growth medium. Confocal immunofluorescence microscopy revealed that the CLN3 protein is localized to the lysosomal compartment. These results provide evidence that Batten disease can be classified as a member of lysosomal diseases.

Biological Transport↗
PubMed2001

Whi3 binds the mRNA of the G1 cyclin CLN3 to modulate cell fate in budding yeast.

Eukaryotic cells commit in G1 to a new mitotic cycle or to diverse differentiation processes. Here we show that Whi3 is a negative regulator of Cln3, a G1 cyclin that promotes transcription of many genes to trigger the G1/S transition in budding yeast. Whi3 contains an RNA-recognition motif that specifically binds the CLN3 mRNA, with no obvious effects on Cln3 levels, and localizes the CLN3 mRNA into discrete cytoplasmic foci. This is the first indication that G1 events may be regulated by locally restricting the synthesis of a cyclin. Moreover, Whi3 is also required for restraining Cln3 function in meiosis, filamentation, and mating, thus playing a key role in cell fate determination in budding yeast.

Amino Acid Motifs↗
PubMed1999

CLN3 expression is sufficient to restore G1-to-S-phase progression in Saccharomyces cerevisiae mutants defective in translation initiation factor eIF4E.

The essential cap-binding protein (eIF4E) of Saccharomyces cerevisiae is encoded by the CDC33 (wild-type) gene, originally isolated as a mutant, cdc33-1, which arrests growth in the G1 phase of the cell cycle at 37 degrees C. We show that other cdc33 mutants also arrest in G1. One of the first events required for G1-to-S-phase progression is the increased expression of cyclin 3. Constructs carrying the 5'-untranslated region of CLN3 fused to lacZ exhibit weak reporter activity, which is significantly decreased in a cdc33-1 mutant, implying that CLN3 mRNA is an inefficiently translated mRNA that is sensitive to perturbations in the translation machinery. A cdc33-1 strain expressing either stable Cln3p (Cln3-1p) or a hybrid UBI4 5'-CLN3 mRNA, whose translation displays decreased dependence on eIF4E, arrested randomly in the cell cycle. In these cells CLN2 mRNA levels remained high, indicating that Cln3p activity is maintained. Induction of a hybrid UBI4 5'-CLN3 message in a cdc33-1 mutant previously arrested in G1 also caused entry into a new cell cycle. We conclude that eIF4E activity in the G1-phase is critical in allowing sufficient Cln3p activity to enable yeast cells to enter a new cell cycle.

5' Untranslated Regions↗
PubMed1999

A murine model for juvenile NCL: gene targeting of mouse Cln3.

JNCL is a neurodegenerative disease of childhood caused by mutations in the CLN3 gene. A mouse model for JNCL was created by disrupting exons 1-6 of Cln3, resulting in a null allele. Cln3 null mice appear clinically normal at 5 months of age; however, like JNCL patients, they exhibit intracellular accumulation of autofluorescent material. A second approach will generate mice in which exons 7 and 8 of Cln3 are deleted, mimicking the common mutation in JNCL patients.

Animals↗
PubMed1999

Expression studies of CLN3 protein (battenin) in fusion with the green fluorescent protein in mammalian cells in vitro.

The gene for Batten disease, the CLN3 gene, encodes a novel, highly hydrophobic, multitransmembrane protein, predicted to consist of 438 amino acid residues. We have expressed a full-length CLN3 protein in fusion with green fluorescent protein in various cell lines to provide its initial biochemical characterization and subcellular localization. By using Western blotting, Percoll density gradient fractionation, and Triton X-114 extraction, we demonstrate that the product of the CLN3 gene, which we call battenin, in mammalian expression system studied is a highly glycosylated protein of lysosomal membrane. In addition our data suggest that CLN3 protein is processed proteolytically in acidic compartments of the cell. Thus, battenin represents the novel constituent of a growing family of lysosomal membrane proteins.

Animals↗
PubMed1999

Targeted disruption of the Cln3 gene provides a mouse model for Batten disease. The Batten Mouse Model Consortium [corrected].

Batten disease, a degenerative neurological disorder with juvenile onset, is the most common form of the neuronal ceroid lipofuscinoses. Mutations in the CLN3 gene cause Batten disease. To facilitate studies of Batten disease pathogenesis and treatment, a murine model was created by targeted disruption of the Cln3 gene. Mice homozygous for the disrupted Cln3 allele had a neuronal storage disorder resembling that seen in Batten disease patients: there was widespread and progressive intracellular accumulation of autofluorescent material that by EM displayed a multilamellar rectilinear/fingerprint appearance. Inclusions contained subunit c of mitochondrial ATP synthase. Mutant animals also showed neuropathological abnormalities with loss of certain cortical interneurons and hypertrophy of many interneuron populations in the hippocampus. Finally, as is true in Batten disease patients, there was increased activity in the brain of the lysosomal protease Cln2/TPP-1. Our findings are evidence that the Cln3-deficient mouse provides a valuable model for studying Batten disease.

Animals↗
PubMed2005

Deletion of the Caenorhabditis elegans homologues of the CLN3 gene, involved in human juvenile neuronal ceroid lipofuscinosis, causes a mild progeric phenotype.

The CLN3 gene is involved in juvenile neuronal ceroid lipofuscinosis (JNCL), or Batten-Spielmeyer-Vogt disease, a severe hereditary neurodegenerative lysosomal storage disorder characterized by progressive disease pathology, with loss of vision as the first symptom. Another characteristic of JNCL is the lysosomal accumulation of autofluorescent lipopigments, forming fingerprint storage patterns visible by electron microscopy. The function of the CLN3 protein is still unknown, although the evolutionarily conserved CLN3 protein is being functionally analysed using different experimental models. We have explored the potential of the nematode Caenorhabditis elegans as a model for Batten disease in order to bridge the gap between the unicellular yeast and very complex mouse JNCL models. C. elegans has three genes homologous to CLN3, for each of which deletion mutants were isolated. Cln-3.1 deletion mutants have a decreased lifespan, and cln-3.2 deletion mutants a decreased brood size. However, the neuronal or movement defects and aberrant lipopigment distribution or accumulation observed in JNCL were not found in the worms. To detect possible redundancy, single deletion mutants were crossed to obtain double and triple mutants, which were viable but showed no JNCL-specific defects. The cln-3 triple mutants show a more prominent decrease in lifespan and brood size, the latter most conspicuously at the end of the egg-laying period, suggesting premature ageing. To focus our functional analysis we examined the C. elegans cln-3 expression patterns, using promoter-GFP (green fluorescent protein) gene fusions. Fluorescence patterns suggest cln-3.1 expression in the intestine, cln-3.2 expression in the hypoderm, and cln-3.3 expression in intestinal muscle, male-specific posterior muscle and hypoderm. Further life stage- and tissue-specific analysis of the processes causing the phenotype of the cln-3 triple mutants may provide more information about the function of the cln-3 protein and contribute to a better understanding of the basic processes affected in Batten disease patients.

Alleles↗