scholarly journals Two Functional Copies of the DGCR6 Gene Are Present on Human Chromosome 22q11 Due to a Duplication of an Ancestral Locus

2001 ◽  
Vol 11 (2) ◽  
pp. 208-217
Author(s):  
Lisa Edelmann ◽  
Pavel Stankiewicz ◽  
Elizabeth Spiteri ◽  
Raj K. Pandita ◽  
Lisa Shaffer ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Primate Species ◽  
Region Gene ◽  
Chromosome 22Q11 ◽  
Expression Studies ◽  
Low Copy Repeats ◽  
Duplicate Locus ◽  
Human Chromosome 22Q11 ◽  
Velo Cardio Facial Syndrome ◽  
Functional Copy

The DGCR6 (DiGeorge critical region) gene encodes a putative protein with sequence similarity to gonadal(gdl), a Drosophila melanogaster gene of unknown function. We mapped the DGCR6 gene to chromosome 22q11 within a low copy repeat, termed sc11.1a, and identified a second copy of the gene, DGCR6L, within the duplicate locus, termed sc11.1b. Both sc11.1 repeats are deleted in most persons with velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS), and they map immediately adjacent and internal to the low copy repeats, termed LCR22, that mediate the deletions associated with VCFS/DGS. We sequenced genomic clones from both loci and determined that the putative initiator methionine is located further upstream than originally described, but in a position similar to the mouse and chicken orthologs.DGCR6L encodes a highly homologous, functional copy ofDGCR6, with some base changes rendering amino acid differences. Expression studies of the two genes indicate that both genes are widely expressed in fetal and adult tissues. Evolutionary studies using FISH mapping in several different species of ape combined with sequence analysis of DGCR6 in a number of different primate species indicate that the duplication is at least 12 million years old and may date back to before the divergence of Catarrhines from Platyrrhines, 35 mya. These data suggest that there has been selective evolutionary pressure toward the functional maintenance of both paralogs. Interestingly, a full-length HERV-K provirus integrated into the sc11.1a locus after the divergence of chimpanzees and humans.

scholarly journals The Organization of the γ-Glutamyl Transferase Genes and Other Low Copy Repeats in Human Chromosome 22q11

1997 ◽  
Vol 7 (5) ◽  
pp. 522-531 ◽  
Author(s):  
John E. Collins ◽  
Andrew J. Mungall ◽  
Karen L. Badcock ◽  
Joanne M. Fay ◽  
Ian Dunham
Keyword(s):  
Human Chromosome ◽  
Chromosome 22Q11 ◽  
Low Copy Repeats ◽  
Human Chromosome 22Q11 ◽  
Glutamyl Transferase

scholarly journals A spontaneous chromosomal amplification of the ADH2 gene in Saccharomyces cerevisiae.

Genetics ◽  
1992 ◽  
Vol 130 (2) ◽  
pp. 263-271
Author(s):  
C E Paquin ◽  
M Dorsey ◽  
S Crable ◽  
K Sprinkel ◽  
M Sondej ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Sequence Similarity ◽  
Resistant Mutant ◽  
Yeast Genome ◽  
Crossing Over ◽  
Antimycin A ◽  
Extra Copy ◽  
Multiple Copies ◽  
Or Gene ◽  
Functional Copy

Abstract A spontaneous antimycin A-resistant mutant carrying approximately four extra copies of ADH2 on chromosome XII was isolated from yeast strain 315-1D which lacks a functional copy of ADH1 and thus is antimycin A-sensitive. The additional copies of the normally glucose-repressed ADH2 are expressed during growth on glucose accounting for the antimycin A resistance. These extra copies are inserted into nonadjacent ribosomal DNA sequences (rDNA) near the recombination stimulating sequence HOT1. Each extra copy of the ADH2 gene (1548 bp) replaces most of the 37S transcript (approximately 7400 bp) in one of the approximately 200 copies of the rDNA present in the yeast genome. All four extra copies of ADH2 are lost at a rate of approximately 1 x 10(-5) deletions per cell per generation. One of the joints between the rDNA and ADH2 DNA is located 7 nucleotides downstream from 20 adenine residues in the normal copy of ADH2. This joint occurs at the end of a stretch of 16-29 thymidines in the rDNA which has been expanded to 57-59 thymidines. The other novel joint is located in a short region of sequence similarity between ADH2 and the rDNA. These observations suggest that amplification of ADH2 was a two step process: first the ADH2 gene was inserted into the rDNA, then multiple copies were generated by unequal crossing over or gene conversion within the rDNA.

Schizophrenia and Hypocalcaemia: Variable Phenotype of Deletion at Chromosome 22q11

1999 ◽  
Vol 33 (5) ◽  
pp. 760-762 ◽  
Author(s):  
L. Y. Chow ◽  
Merce Garcia-Barcelo ◽  
Y. K. Wing ◽  
Mary M. Y. Waye
Keyword(s):  
Phenotypic Variability ◽  
In Situ Hybridisation ◽  
Psychotic Symptoms ◽  
22Q11 Deletion ◽  
Deletion 22Q11 ◽  
Chromosome 22Q11 ◽  
Wide Range ◽  
Variable Phenotype ◽  
Velo Cardio Facial Syndrome

Objective: The aim of this paper is to report the diagnosis of velo-cardio-facial syndrome (VCFS) in a patient presenting with schizophrenia and hypocalcaemia. Screening of deletion 22q11 in patients with schizophrenia is discussed. Clinical picture: We report a schizophrenic patient presenting with hypocalcaemia as the only feature of VCFS. Deletion 22q11 was confirmed by fluorescent in situ hybridisation (FISH). Treatment: The patient was treated with haloperidol 3 mg/day with resolution of psychotic symptoms. Outcome: The patient harboured some residual psychotic symptoms probably related to her irregular compliance. Conclusions: The wide range of phenotypic variability of VCFS makes screening of 22q11 deletion in schizophrenia difficult. It is proposed that screening of 22q11 deletion in schizophrenia should be selectively targeted only at patients with specific features of VCFS highly predictive of the presence of 22q11 deletion.

The Breakpoint Cluster Region Gene on Chromosome 22q11 is Associated with Bipolar Disorder

2005 ◽  
Vol 57 (10) ◽  
pp. 1097-1102 ◽  
Author(s):  
Ryota Hashimoto ◽  
Takeya Okada ◽  
Tadafumi Kato ◽  
Asako Kosuga ◽  
Masahiko Tatsumi ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Region Gene ◽  
Breakpoint Cluster Region ◽  
Cluster Region ◽  
Chromosome 22Q11

scholarly journals Comparison of S-layer secretion genes in freshwater caulobacters

2004 ◽  
Vol 50 (9) ◽  
pp. 751-766 ◽  
Author(s):  
Mihai Iuga ◽  
Peter Awram ◽  
John F Nomellini ◽  
John Smit
Keyword(s):  
Protein Secretion ◽  
Caulobacter Crescentus ◽  
Sequence Similarity ◽  
Atp Binding ◽  
Type I ◽  
C Terminus ◽  
Expression Studies ◽  
Size Groups ◽  
Membrane Fusion Proteins ◽  
Atp Binding Cassette

Our freshwater caulobacter collection contains about 40 strains that are morphologically similar to Caulobacter crescentus. All elaborate a crystalline protein surface (S) layer made up of protein monomers 100–193 kDa in size. We conducted a comparative study of S-layer secretion in 6 strains representing 3 size groups of S-layer proteins: small (100–108 kDa), medium (122–151 kDa), and large (181–193 kDa). All contained genes predicted to encode ATP-binding cassette transporters and membrane fusion proteins highly similar to those of C. crescentus, indicating that the S-layer proteins were all secreted by a type I system. The S-layer proteins' C-termini showed unexpectedly low sequence similarity but contained conserved residues and predicted secondary structure features typical of type I secretion signals. Cross-expression studies showed that the 6 strains recognized secretion signals from C. crescentus and Pseudomonas aeruginosa and similarly that C. crescentus was able to secrete the S-layer protein C-terminus of 1 strain examined. Inactivation of the ATP-binding cassette transporter abolished S-layer protein secretion, indicating that the type I transporter is necessary for S-layer protein secretion. Finally, while all of the S-layer proteins of this subset of strains were secreted by type I mechanisms, there were significant differences in genome positions of the transporter genes that correlated with S-layer protein size.Key words: freshwater caulobacter, S-layer, type I secretion system, ABC transporter.

scholarly journals Structural brain abnormalities associated with deletion at chromosome 22q11

2001 ◽  
Vol 178 (5) ◽  
pp. 412-419 ◽  
Author(s):  
Therese Van Amelsvoort ◽  
Eileen Daly ◽  
Dene Robertson ◽  
John Suckling ◽  
Virginia Ng ◽  
...  
Keyword(s):  
White Matter ◽  
Learning Disability ◽  
Brain Anatomy ◽  
White Matter Volume ◽  
Brain Abnormalities ◽  
Temporal Lobes ◽  
Chromosome 22Q11 ◽  
High Prevalence ◽  
Velo Cardio Facial Syndrome ◽  
Regional Brain Volume

BackgroundVelo-cardio-facial syndrome (VCFS) is associated with deletions in the q11 band of chromosome 22, learning disability and psychosis, but the neurobiological basis is poorly understood.AimsTo investigate brain anatomy in adults with VCFS.MethodMagnetic resonance imaging was used to study 10 patients with VCFS and 13 matched controls. We carried out three analyses: qualitative; traced regional brain volume; and measurement of grey and white matter volume.ResultsThe subjects with VCFS had: a high prevalence of white matter hyperintensities and abnormalities of the septum pellucidum; a significantly smaller volume of cerebellum; and widespread differences in white matter bilaterally and regional specific differences in grey matter in the left cerebellum, insula, and frontal and right temporal lobes.ConclusionsDeletion at chromosome 22q11 is associated with brain abnormalities that are most likely neurodevelopmental and may partially explain the high prevalence of learning disability and psychiatric disorder in VCFS.

Isolation of anonymous DNA markers for human chromosome 22q11 from a flow-sorted library, and mapping using hybrids from patients with DiGeorge syndrome

1992 ◽  
Vol 89 (1) ◽  
pp. 73-78 ◽  
Author(s):  
A.M. Sharkey ◽  
L. McLaren ◽  
M. Carroll ◽  
J. Fantes ◽  
D. Green ◽  
...  
Keyword(s):  
Human Chromosome ◽  
Dna Markers ◽  
Digeorge Syndrome ◽  
Chromosome 22Q11 ◽  
Human Chromosome 22Q11

scholarly journals Low-Copy Repeats Mediate the Common 3-Mb Deletion in Patients with Velo-cardio-facial Syndrome

1999 ◽  
Vol 64 (4) ◽  
pp. 1076-1086 ◽  
Author(s):  
Lisa Edelmann ◽  
Raj K. Pandita ◽  
Bernice E. Morrow
Keyword(s):  
Low Copy Repeats ◽  
The Common ◽  
Velo Cardio Facial Syndrome

scholarly journals Nup84, A Novel Nucleoporin That Is Associated With CAN/Nup214 on the Cytoplasmic Face of the Nuclear Pore Complex

1997 ◽  
Vol 137 (5) ◽  
pp. 989-1000 ◽  
Author(s):  
Ricardo Bastos ◽  
Lluis Ribas de Pouplana ◽  
Mark Enarson ◽  
Khaldon Bodoor ◽  
Brian Burke
Keyword(s):  
Nuclear Pore Complex ◽  
Sequence Similarity ◽  
Coiled Coil ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Significant Sequence Similarity ◽  
Expression Studies ◽  
Cytoplasmic Face ◽  
Secondary Structure Predictions ◽  
Pore Complexes

The short filaments extending from the cytoplasmic face of nuclear pore complexes are thought to contain docking sites for nuclear import substrates. One component of these filaments is the large O-linked glycoprotein CAN/Nup214. Immunoprecipitation studies carried out under nondenaturing conditions, and using a variety of antibodies, reveal a novel nonglycosylated nucleoporin, Nup84, that is tightly associated with CAN/Nup214. Consistent with such an association, Nup84 is found to be exposed on the cytoplasmic face of the nuclear pore complex. cDNA sequence analyses indicate that Nup84 contains neither the GLFG nor the XFXFG repeats that are a characteristic of a number of other nuclear pore complex proteins. Secondary structure predictions, however, suggest that Nup84 contains a coiled–coil COOH-terminal domain, a conclusion supported by the observation of significant sequence similarity between this region of the molecule and various members of the tropomyosin family. Mutagenesis and expression studies indicate that the putative coiled–coil domain is required for association with the cytoplasmic face of the nuclear pore complex, whereas it is the NH2-terminal region of Nup84 that contains the site of interaction with CAN/Nup214. These findings suggest a model in which Nup84 may function in the attachment of CAN/Nup214 to the central framework of the nuclear pore complex. In this way, Nup84 could play a central role in the organization of the interface between the pore complex and the cytoplasm.

Velo-cardio-facial syndrome, schizophrenia and deletion at chromosome 22q11

1998 ◽  
Vol 42 (2) ◽  
pp. 184-188 ◽  
Author(s):  
L. Y. Chow ◽  
M. M. Y. Waye ◽  
M. Garcia-Barcelo ◽  
H. F. K. Chiu ◽  
K. P. Fung ◽  
...  
Keyword(s):  
Chromosome 22Q11 ◽  
Velo Cardio Facial Syndrome
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