Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Miller-Dieker syndrome (MDS) is a multiple malformation syndrome characterized by classical lissencephaly and a characteristic facies. It is associated with visible or submicroscopic deletions within chromosome band 17p13.3. Lissencephaly without facial dysmorphism has also been observed and is referred to as isolated lissencephaly sequence (ILS). Apparently partial and non-overlapping deletions of the 5' or 3' end of a candidate gene LIS1 in one ILS and one MDS patient had suggested that MDS was a single gene disorder, and that LIS1 spans in excess of 400 kb. However, the originally presumed 5' end of LIS1 was found to belong to the 14-33 epsilon gene residing more distally on 17p13.3. We have now isolated the correct 5' end of LIS1, constructed a approximately 500 kb genomic contig encompassing LIS1, and estimated its gene to be approximately 80 kg. Fluorescence in situ hybridization analysis of an ILS patient with a de novo balanced translocation, as well as analysis of several other key MDS and ILS deletion patients, localizes the lissencephaly critical region within the LIS1 gene. Therefore, LIS1 remains the strongest candidate gene for the lissencephaly phenotype in ILS and MDS. Our analyses also suggest that additional genes distal to LIS1 may be responsible for the facial dysmorphology and other abnormalities seen in MDS but not in ILS patients, supporting our original concept MDS as a contiguous gene deletion syndrome.
Hum Mol Genet 1997 Feb
PMID:A revision of the lissencephaly and Miller-Dieker syndrome critical regions in chromosome 17p13.3. 906 34

Classical lissencephaly (smooth brain) or generalized agyria-pachygyria is a severe brain malformation which results from an arrest of neuronal migration at 9-13 weeks gestation. It has been observed in several malformation syndromes including Miller-Dieker syndrome (MDS) and isolated lissencephaly sequence (ILS). A gene containing beta-transducin like repeats, now known as LIS1, was previously mapped to the ILS/MDS chromosome region on 17p13.3. We recently localized the classical lissencephaly critical region to the LIS1 gene locus by molecular analysis of key ILS and MDS patients. We have now characterized the structure of LIS1, which consists of 11 exons, and have searched for the presence of subtle mutations in 19 ILS patients who showed no gross rearrangements of LIS1. Single strand conformational polymorphism (SSCP) analysis revealed band-shifts for three patients, each involving a different coding exon, which were not observed in their respective parental DNAs. Sequence analysis identified these de novo mutations as dA --> dG transition in exon VI at nucleotide 446, a dC --> dT transition in exon VIII at nucleotide 817, and a 22 bp deletion at the exon IX-intron 9 junction from nucleotide 988 to 1,002+7, which causes skipping of exon IX in the mature LIS1 transcript. These changes are predicted to result in an H149R amino acid substitution, an R273X premature translation termination, and abolition of amino acids 301-334, in the respective LIS1 proteins. These data thus confirm LIS1 as the gene responsible for classical lissencephaly in ILS and MDS.
Hum Mol Genet 1997 Feb
PMID:Point mutations and an intragenic deletion in LIS1, the lissencephaly causative gene in isolated lissencephaly sequence and Miller-Dieker syndrome. 906 35

Classical lissencephaly (LIS) is a neuronal migration disorder resulting in brain malformation, epilepsy and mental retardation. Deletions or mutations of LIS1 on 17p13.3 and mutations in XLIS ( DCX ) on Xq22.3-q23 produce LIS. Direct DNA sequencing of LIS1 and XLIS was performed in 25 children with sporadic LIS and no deletion of LIS1 by fluorescence in situ hybridization. Mutations of LIS1 were found by sequencing ( n = 8) and Southern blot ( n = 2) in a total of 10 patients (40%) of both sexes and mutations of XLIS in five males (20%). Combined with previous data, deletions or mutations of these two genes account for approximately 76% of isolated LIS. These data demonstrate that LIS1 and XLIS mutations cause the majority of, though not all, human LIS. The mutations in LIS1 were predicted to result in protein truncation in six of eight patients and splice site mutations in two, all of which disrupt one or more of the seven WD40 repeats contained in the LIS1 protein. Point mutations in XLIS identified the C-terminal serine/proline-rich region as potentially important for protein function. The patients with mutations were included in a genotype-phenotype analysis of 32 subjects with deletions or other mutations of these two genes. Whereas the brain malformation due to LIS1 mutations was more severe over the parietal and occipital regions, XLIS mutations produced the reverse gradient, which was more severe over the frontal cortex. The distinct LIS patterns suggest that LIS1 and XLIS may be part of overlapping, but distinct, signaling pathways that promote neuronal migration.
Hum Mol Genet 1998 Dec
PMID:LIS1 and XLIS (DCX) mutations cause most classical lissencephaly, but different patterns of malformation. 981 18

Lissencephaly is a relatively common brain malformation. Lissencephaly type 1 is characterized by the smooth appearance of the cortex and the presence of four abnormally positioned layers instead of the normal six. Lissencephaly is considered to be an abnormality in neuronal migration. The gene mutated in type 1 lissencephaly was cloned by us and designated LIS1. Recently, several genes involved in cortical development have been cloned in the mouse. In human an additional X-linked lissencephaly gene has been identified. We summarize here our current knowledge on the LIS1 gene and its function. It has been identified as a non-catalytic subunit of PAF-acetylhydrolase, a heterotrimeric enzyme which inactivates the platelet-activating factor (PAF). In addition, we have demonstrated that LIS1 interacts with tubulin, and affects the dynamics properties of microtubles. LIS1 contains seven WD repeats and may structurally resemble the beta-subunit of heterotrimeric G proteins. Interestingly, the catalytic subunit of PAF-acetylhydrolase was found to resemble the alpha subunit of heterotrimeric G proteins. We raise the possibility that LIS1 is part of an intracellular signaling pathway involved in neuronal migration.
Int J Mol Med 1998 May
PMID:Abnormal cortical development; towards elucidation of the LIS1 gene product function (review). 985 6

X-linked lissencephaly is a severe brain malformation affecting males. Recently it has been demonstrated that the doublecortin gene is implicated in this disorder. In order to study the function of Doublecortin, we analyzed the protein upon transfection of COS cells. Doublecortin was found to bind to the microtubule cytoskeleton. In vitro assays (using biochemical methods, DIC microscopy and electron microscopy) demonstrate that Doublecortin binds microtubules directly, stabilizes them and causes bundling. In vivo assays also show that Doublecortin stabilizes microtubules and causes bundling. Doublecortin is a basic protein with an iso-electric point of 10, typical of microtubule-binding proteins. However, its sequence contains no known microtubule-binding domain(s). The results obtained in this study with Doublecortin and our previous work on another lissencephaly gene ( LIS1 ) emphasize the central role of regulation of microtubule dynamics and stability during neuronal morphogenesis.
Hum Mol Genet 1999 Sep
PMID:Doublecortin, a stabilizer of microtubules. 1044 22

Subcortical band heterotopia (SBH) are bilateral and symmetric ribbons of gray matter found in the central white matter between the cortex and the ventricular surface, which comprises the less severe end of the lissencephaly (agyria-pachygyria-band) spectrum of malformations. Mutations in DCX (also known as XLIS ) have previously been described in females with SBH. We have now identified mutations in either the DCX or LIS1 gene in three of 11 boys studied, demonstrating for the first time that mutations of either DCX or LIS1 can cause SBH or mixed pachygyria-SBH (PCH-SBH) in males. All three changes detected are missense mutations, predicted to be of germline origin. They include a missense mutation in exon 4 of DCX in a boy with PCH-SBH (R78H), a different missense mutation in exon 4 of DCX in a boy with mild SBH and in his mildly affected mother (R89G) and a missense mutation in exon 6 of LIS1 in a boy with SBH (S169P). The missense mutations probably account for the less severe brain malformations, although other patients with missense mutations in the same exons have had diffuse lissencephaly. Therefore, it appears likely that the effect of the specific amino acid change on the protein determines the severity of the phenotype, with some mutations enabling residual protein function and allowing normal migration in a larger proportion of neurons. However, we expect that somatic mosaic mutations of both LIS1 and DCX will also prove to be an important mechanism in causing SBH in males.
Hum Mol Genet 1999 Sep
PMID:Subcortical band heterotopia in rare affected males can be caused by missense mutations in DCX (XLIS) or LIS1. 1044 40

The RHO1 gene encodes a yeast homolog of the mammalian RhoA protein. Rho1p is localized to the growth sites and is required for bud formation. We have recently shown that Bni1p is one of the potential downstream target molecules of Rho1p. The BNI1 gene is implicated in cytokinesis and the establishment of cell polarity in Saccharomyces cerevisiae but is not essential for cell viability. In this study, we screened for mutations that were synthetically lethal in combination with a bni1 mutation and isolated two genes. They were the previously identified PAC1 and NIP100 genes, both of which are implicated in nuclear migration in S. cerevisiae. Pac1p is a homolog of human LIS1, which is required for brain development, whereas Nip100p is a homolog of rat p150(Glued), a component of the dynein-activated dynactin complex. Disruption of BNI1 in either the pac1 or nip100 mutant resulted in an enhanced defect in nuclear migration, leading to the formation of binucleate mother cells. The arp1 bni1 mutant showed a synthetic lethal phenotype while the cin8 bni1 mutant did not, suggesting that Bni1p functions in a kinesin pathway but not in the dynein pathway. Cells of the pac1 bni1 and nip100 bni1 mutants exhibited a random distribution of cortical actin patches. Cells of the pac1 act1-4 mutant showed temperature-sensitive growth and a nuclear migration defect. These results indicate that Bni1p regulates microtubule-dependent nuclear migration through the actin cytoskeleton. Bni1p lacking the Rho-binding region did not suppress the pac1 bni1 growth defect, suggesting a requirement for the Rho1p-Bni1p interaction in microtubule function.
Mol Cell Biol 1999 Dec
PMID:Bni1p regulates microtubule-dependent nuclear migration through the actin cytoskeleton in Saccharomyces cerevisiae. 1056 27

We evaluated the postoperative adjuvant chemotherapy by UFT using the primary tumor amputation-pulmonary metastasis model. When Lewis lung carcinoma (LLC) primary tumors on the hind foot pad grew palpable, they were amputated on two different days. In experiment (A) (earlier amputation model), micrometastases were detected on the day of amputation only by the histopathological examination. In the experiment (B) (later amputation model), nodules could be determined even by necropsy. Long-term (60-day) consecutive administration of UFT (22 mg/kg/day), which produced no body weight loss, markedly prolonged the survival period in experiment (A) (ILS: over 118%), 1 of the 15 mice being cured. UFT had a relatively weak but significant effect (67% of ILS) in schedule (B). Using the same model, we examined the inhibitory effect of UFT (2-week administration) on the number of metastatic nodules. A significant decrease of metastatic nodules was observed by UFT with both amputation schedules, but its effect was superior with schedule (A). In the same model using Colon 26 PMF-15, UFT markedly prolonged the survival period of mice (150% of ILS) and significantly decreased the metastatic nodules (86% inhibition). The dose of UFT used was relatively low, and did not significantly inhibit the growth of large tumors. However, the sensitivity to the micrometastases was high. These findings suggest that the postoperative adjuvant chemotherapy by the long-term consecutive administration of UFT would be effective for clinical cancer especially in curatively resected cases.
Int J Mol Med 2000 Apr
PMID:Experimental postoperative adjuvant chemotherapy by UFT using primary tumor amputation model. 1071 50

Magnetic resonance imaging is now used routinely in the evaluation of developmental and neurological disorders and provides exquisite images of the living human brain. Consequently, it is evident that cortical malformations are more common than previously thought. Among the most severe is classical lissencephaly, in which the cortex lacks the complex folding that characterizes the normal human brain. Lissencephaly includes agyria and pachygyria, and merges with subcortical band heterotopia. Current molecular genetic techniques combined with the identification of affected patients have enabled the detection of two of the genes responsible: LIS1 (PAFAH1B1) on chromosome 17 and DCX (doublecortin) on the X chromosome. This review highlights the discovery of these genes and discusses the advances made in understanding the molecular basis of cortical development and improvements in diagnosis and genetic counseling.
Mol Med Today 2000 Jul
PMID:Lissencephaly and subcortical band heterotopia: molecular basis and diagnosis. 1085 64

Formation of our highly structured human brain involves a cascade of events, including differentiation, fate determination, and migration of neural precursors. In humans, unlike many other organisms, the cerebral cortex is the largest component of the brain. As in other mammals, the human cerebral cortex is located on the surface of the telencephalon and generally consists of six layers that are formed in an orderly fashion. During neuronal development, newly born neurons, moving in a radial direction, must migrate through previously formed layers to reach their proper cortical position. This is one of several neuronal migration routes that takes place in the developing brain; other modes of migration are tangential. Abnormal neuronal migration may in turn result in abnormal development of the cortical layers and deleterious consequences, such as Lissencephaly. Lissencephaly, a severe brain malformation, can be caused by mutations in one of two known genes: LIS1 and doublecortin (DCX). Recent in vitro and in vivo studies, report on possible functions for these gene products.
Mol Neurobiol
PMID:The unfolding story of two lissencephaly genes and brain development. 1096 19


1 2 3 4 5 Next >>