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1.
Cecilie Boysen Christopher Carlson Eran Hood Leroy Hood Deborah A. Nickerson 《Immunogenetics》1996,44(2):121-127
The T-cell receptor (TCR) is a highly variable molecule composed of two polypeptide chains that recognize antigenic peptides
in the context of major histocompatibility complex (MHC) molecules. In this study, we describe a sequence-based search for
germline polymorphisms in the variable (V) gene segments of the human TCRA/D locus. Thirty different V gene segments were amplified from six to eight unrelated individuals and sequenced from low melting point agarose. Twenty-seven
polymorphisms were identified in 15 V gene segments. These polymorphisms are mainly single nucleotide substitutions, but an insertion/deletion polymorphism and
a single dinucleotide repeat with variable length were also seen. Of the 15 sequence variations found in the coding regions,
six are silent and nine encode amino acid changes. All of the amino acid changes are found at non-conserved residues, frequently
in the hypervariable regions, where they may influence MHC and/or peptide recognition. Therefore, it is possible that germline
variations in TCR genes could influence an individual’s immune response, and may also contribute to susceptibility to diseases such as autoimmunity.
Received: 9 January 1996 / Revised: 22 February 1996 相似文献
2.
J. Sánchez-Torres P. Pérez R. I. Santamaría 《Applied microbiology and biotechnology》1996,46(2):149-155
Several alkalophilic Bacillus spp. strains were selected for their capacity to produce alkaline cellulases. Culture supernatants of these strains showed
optimal cellulase activities between pH 8 and 9 and they were stable from pH 6 to pH 12. A cellulase gene (celB1) from the alkalophilic Bacillus sp. strain N186-1 was cloned in Escherichia coli using polymerase chain reaction techniques. The cloned gene was present in a 2.539-bp HindIII fragment and its nucleotide sequence was determined. The coding sequence showed an open-reading frame encoding 389 amino
acids. The amino acid sequence, deduced from the nucleotide sequence, permitted us to include it in family 5 (or A) of the
glycosyl hydrolases. The complete open-reading frame of celB1 was cloned in the plasmid pET-11d and expressed in E. coli BL21 (DE3), in which a protein of 39 kDa was obtained in the cytoplasm; however, no endoglucanase activity was detected.
A second construction in pET-12a allowed the production of a 39-kDa protein located in the periplasmic space of E. coli that had endoglucanase activity. The protein produced has optimal activity at pH 7 and 50°C and it retains more than 70%
of its activity after incubation for 1 h at pH 12.
Received: 27 December 1995/Received revision: 14 March 1996/Accepted: 25 March 1996 相似文献
3.
Amino acid and protein analyses have allowed the construction of a model for the C4-based Rodgers and Chido blood group antigens.
The single low-frequency allele (WH) in this blood group system, however, has not been characterized at the molecular level. Two WH+ donors were studied by C4 agarose gel electrophoreses, immunoblot studies using monoclonal anti-Rg: 1 or anti-Ch: 1, serological
phenotyping, polymerase chain reaction-restriction fragment length polymorphism of their C4 genes, and DNA sequencing of the WH allele. The first donor had the C4A1, A3 phenotype; the C4A1 carried Ch: 1, 3, 6 (thus exhibiting reversed antigenicity)
and the C4A3 carried the WH antigen. The amino acid sequence of the WH allele was PCPVLD at positions 1101 – 1106, S at position 1157, and VDLL at positions 1188 – 1191. A second donor typed as
C4A2, A4, B1 and was also WH+. Immunoblot analysis showed that a C4B1 protein expressed Rg: 1. Sequence analysis of the C4B genes showed the amino acids LSPVIH at positions 1101 – 1106, S at position 1157, and ADLR at positions 1188 – 1191. Thus,
the WH antigen is a conformational epitope that can arise through different mechanisms on either a C4A or C4B gene.
Received: 22 November 1995 / Revised: 19 February 1996 相似文献
4.
5.
Nassima Fodil Laurent Laloux Valérie Wanner Philippe Pellet Georges Hauptmann Nobuhisa Mizuki Hidetoshi Inoko Thomas Spies Ioannis Theodorou Seiamak Bahram 《Immunogenetics》1996,44(5):351-357
The hallmark of the classical major histocompatibility complex (MHC) class I molecules is their astonishing level of polymorphism,
a characteristic not shared by the nonclassical MHC class I genes. A distinct family of MHC class I genes has been recently identified within the human MHC class I region. The MICA (MHC class I chain-related A) gene in this family is a highly divergent member of the MHC class I family and has a unique pattern of tissue expression. We have sequenced exons encoding the extracellular α1, α2,
and α3 domains of the MICA gene from twenty HLA homozygous typing cell lines and four unrelated individuals. We report the identification of eleven new alleles defined by
a total of twenty-two amino acid substitutions. Thus, the total number of MICA alleles is sixteen. Interestingly, a tentative superimposition of MICA variable residues on the HLA-A2 structure reveals a unique pattern of distribution, concentrated primarily on the outer edge of the MICA putative antigen
binding cleft, apparently bordering an invariant ligand binding site.
Received: 13 May 1996 / Revised: 29 May 1996 相似文献
6.
T. Yamashita Tomoyuki Fujii Yoshihisa Watanabe Katsushi Tokunaga Kenji Tadokoro Takeo Juji Yuji Taketani 《Immunogenetics》1996,44(3):186-191
Polymorphism of the HLA-G gene in a Japanese population was investigated employing polymerase chain reaction (PCR)-single-strand conformation polymorphism
(SSCP) analysis, PCR sequence-specific oligonucleotide (SSO) analysis, and DNA direct sequencing. Nucleotide sequence variations
in exons 2, 3, and 4 of the HLA-G gene in 54 healthy Japanese individuals were examined. In addition, seven Japanese samples carrying common HLA haplotypes were analyzed. In total, nine single-base substitutions compared with the sequence of G
*
01011 were identified: one in intron 1 (nucleotide position 970), one in exon 2 (the third base of codon 57: G → A), three in intron
2 (1264, 1276, and 1292), three in exon 3 (the third base of codon 93: C → T, the third base of codon 107: A → T, and the
first base of codon 110: C → A), and one in intron 3 (2334). The substitution at codon 110 was non-synonymous and led to an
amino acid substitution from leucine to isoleucine. The other three nucleotide substitutions in exons were synonymous. Through
analysis of combinations of the exon 2, 3, and 4 nucleotide sequences we identified four alleles, which we provisionally designated
GJ1, GJ2, GJ3, and GJ4. The allele frequencies were estimated to be 0.33, 0.16, 0.45, and 0.06, respectively. Nucleotide sequences of GJ1, GJ2, and GJ4 were identical to G
*
01011, the clone 7.0E, and G
*
01013, respectively. GJ3 was a newly observed allele and was officially designated G
*
0104 by the WHO Nomenclature Committee in January 1996. Strong positive associations were observed between HLA-G alleles and HLA-A, -B, or -DRB1 alleles.
Received: 15 February 1996 / Revised: 26 March 1996 相似文献
7.
Benjamin Tycko L. Feng L. Nguyen Aren Francis Allison Hays Wai-Yee Chung Ming-Xin Tang Yaakov Stern Amrik Sahota Hugh Hendrie R. Mayeux 《Human genetics》1996,98(4):430-436
Apolipoprotein-J/clusterin (APOJ/CLI) shares many biological properties with apolipoprotein-Ε (APOE) including, but not limited to, avid binding with β-amyloid peptide. Thus, APOJ/CLI warrants scrutiny as a candidate Alzheimer’s disease (AD) susceptibility gene. We identified seven nucleotide sequence polymorphisms
in APOJ/ CLI, two of which, in exon 7, alter the predicted amino acid sequence. The JVIIB variant is an asparagine-to-histidine substitution,
which deletes a glycosylation signal at amino acid 317; the JVIIC variant is an aspartate-to-asparagine substitution, which
forms a new glycosylation signal at position 328. Both of these coding variants, as well as two neutral polymorphisms in exon
2, were more frequent in African-Americans than Hispanics and were rare in Caucasians. However, no individual coding or noncoding
variant was consistently associated with AD. At the population level, APOJ/CLI polymorphisms are frequent among persons of African descent, but probably do not alter susceptibility to AD.
Received: 14 February 1996 / Revised: 15 April 1996 相似文献
8.
Anupam K. Dattamajumdar Sarah W. Li David P. Jacobson Leroy E. Hood Gamal E. Osman 《Immunogenetics》1996,44(6):432-440
T-cell receptors (Tcrs) of higher organisms play a key role in the specific recognition of self and non-self molecules in the immune system. The
large number of Tcr variable (V) genes have been organized into V gene subfamilies according to their sequence similarity at the nucleotide and amino acid level. We cloned and characterized
four new members of the Tcra-V22 gene subfamily at the genomic level using a simple and sensitive technique that can rapidly clone members of any multi-member
gene family. Sequence analysis reveals that the four Tcra-V22 gene subfamily members have more than 98% sequence similarity in their coding regions, at the nucleotide and amino acid levels.
However, the intron between the leader and the coding region varies up to 7% between members of the Tcra-V22 gene subfamily. Comparison of the multi-member Tcra-V22 gene subfamily with other multi-member Tcra-V gene subfamilies (V2, V8, and V11), shows that Tcra-V22 is unique in that it has multiple members with nearly identical amino acid sequence and which are not inherently pseudogenes.
Sequence similarity analysis of the Tcra-V22 subfamily with the prototypes of all other Tcra-V subfamilies revealed that the Tcra-V22 subfamily has the closest sequence similarity to that of Tcra-V18 (77% at the nucleotide level and 71% at the amino acid level).
Received: 22 March 1996 / Revised: 5 June 1996 相似文献
9.
10.
Southern analysis of Eco RI-digested BALB/c liver DNA reveals four T-cell receptor Tcra-V3-hybridizing DNA fragments, which are of sizes 18.0, 12.0, 8.0, and 2.1 kilobases, respectively. These four Tcra-V3-hybridizing genomic DNA were isolated from a BALB/c genomic library. Restriction and Southern analysis of the genomic DNA
clones showed that each of the Tcra-V3-hybridizing Eco RI DNA fragments harbors only a single Tcra-V3 gene. The DNA sequences of coding regions of the four Tcra-V3 family members were determined. These sequences show very limited divergence from one another. Comparisons of BALB/c Tcra-V3 sequences with published Tcra-V3 sequences expressed in different strains of mice reveal substantial allelic polymorphism. Sequence similarity searches retrieved
homologous rat, cattle, and human genes. The scarcity of coding sequence divergence among members of the Tcra-V3 family and the more substantial allelic polymorphism may be general features of the T-cell receptor V-alpha chain-encoding
gene families.
Received: 11 April 1996 / Revised: 26 May 1996 相似文献
11.
J. M. Crous I. S. Pretorius W. H. van Zyl 《Applied microbiology and biotechnology》1996,46(3):256-260
First-strand cDNA was prepared from mRNA of Aspergillus niger MRC11624 induced on oat spelts xylan. Using the cDNA as a template, the α-L-arabinofuranosidase gene (abf B) was amplified with the polymerase chain reaction technique. The abf B DNA fragment was inserted between the yeast phosphoglycerate kinase I gene promoter (PGK1
P
) and terminator (PGK1
T
) sequences on a multicopy episomal plasmid. The resulting construct PGK1
P
-abf B-PGK1
T
was designated ABF2. The ABF2 gene was expressed successfully in Saccharomyces cerevisiae and functional α-L-arabinofuranosidase was secreted from the yeast cells. The ABF2 nucleotide sequence was determined and verified to encode a 449-amino-acid protein (Abf 2) that is 94% identical to the α-L-arabinofuranosidase B of A. niger N400. Maximum α-L-arabinofuranosidase activities of 0.020 U/ml and 1.40 U/ml were obtained with autoselective recombinant S. cerevisiae strains when grown for 48 h in synthetic and complex medium respectively.
Received: 29 January 1996/Received revision: 3 May 1996/Accepted: 9 May 1996 相似文献
12.
Turunen JA Wessman M Forsblom C Kilpikari R Parkkonen M Pöntynen N Ilmarinen T Ulmanen I Peltonen L Groop PH 《Immunogenetics》2006,58(5-6):331-338
Mutations in the autoimmune regulator (AIRE) gene cause a recessive Mendelian disorder autoimmune polyendocrinopathy syndrome type 1 (APS-1 or autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy). APS-1 patients develop multiorgan autoimmune diseases including type 1 diabetes (prevalence 12%). The AIRE protein controls the central tolerance induction in the thymus by regulating the expression levels of tissue-specific peripheral antigens, such as insulin. We hypothesized that the insulin gene (INS) polymorphisms together with the AIRE variations may predispose individuals to diabetes. The role of the AIRE gene was tested both independently and on the condition of the INS risk genotype in the Finnish type 1 diabetes sample. A total of 733 type 1 diabetic cases and 735 age- and sex-matched healthy controls were used in the analysis. Five common single nucleotide polymorphisms (SNPs) in the AIRE gene were selected from the public database (dbSNP). The −23HphI polymorphism was used as a surrogate marker for the INS gene promoter repeat. The five genotyped SNPs in the AIRE gene showed no evidence of association with type 1 diabetes. As expected, the INS gene polymorphism −23HphI was significantly associated with susceptibility to type 1 diabetes (P=6.8×10−12, χ2 test). When the subclass of patients carrying the homozygote genotype of the INS gene was used in the analysis, the AIRE polymorphisms showed no association with the disease. In conclusion, the AIRE gene does not seem to contribute to disease susceptibility in Finnish type 1 diabetic patients, whereas the insulin gene represents a notable risk factor for disease in this population. 相似文献
13.
S. E. Harrington H. F. J. Bligh W. D. Park C. A. Jones S. R. McCouch 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(5):564-568
The chromosomal position of Starch Branching Enzyme III (SBEIII) was determined via linkage to RFLP markers on an existing
molecular map of rice (Oryza sativa L.). A cDNA of 890 bp was generated using specific PCR primers designed from available SBEIII sequence data and used as a
probe in Southern analysis. The SBEIII cDNA hybridized to multiple restriction fragments, but these fragments mapped to a
single locus on rice chromosome 2, flanked by CDO718 and RG157. The detection of a multiple-copy hybridization pattern suggested the possibility of a tandemly duplicated gene at this
locus. The map location of orthologous SBE genes in maize, wheat, and oat were predicted based on previously published genetic
studies and comparative maps of the grass family.
Received : 5 August 1996 / Accepted : 13 September 1996 相似文献
14.
15.
M. Macek Jr. Milan Macek Sr. Alice Krebsová E. Nash A. Hamosh André Reis Raymonda Varon-Mateeva Nancy E. Maestri Karl Sperling Michael Krawczak G. R. Cutting J. Schmidke 《Human genetics》1997,99(5):565-572
Cystic fibrosis (CF) patients show a high degree of linkage disequilibrium between the CF transmembrane conductance regulator
(CFTR) gene and polymorphisms 5′ of that gene. To determine whether the region 5′ of CFTR contains biologically important sequences, the allele frequencies of six CFTR-linked polymorphisms (metH/MspI, XV-2c/TaqI, CS.7/HhaI, KM19/PstI, MP6-d9/MspI, J44/XbaI) were determined in 417 randomly selected elderly individuals (over 75 years of age) from the Czech population. The elderly
individuals were considered “escapees” of strong selective pressures that had operated during their lifetime, prior to the
introduction of modern health care since 1950. The pooled allele frequencies of the analyzed marker polymorphisms in the elderly
did not significantly differ from published data. However, when analyzed by sex, the allele frequencies of markers CS.7/HhaI and KM19/PstI differed significantly (P < 0.05) between elderly females and males. The allele frequencies of the six polymorphisms were then determined in 646 newborns
and 345 young adults of reproductive age; these individuals were selected in a similar manner and drawn from the same population.
In these control groups, the studied marker polymorphisms exhibited no statistically significant differences between sexes
and/or between individuals of the same sex, only between different age groups. A gradual relative increase in the frequency
of allele “2” of marker CS.7/HhaI was observed from newborn females to elderly women, the overall difference in allele frequencies of this marker polymorphism
between newborn females and elderly women reaching statistical significance (P < 0.05). Interestingly, allele “2” is the major constituent of the extended “B-haplotype”, which is in strong linkage disequilibrium
with common CF alleles. Taken together, our data suggest that the region spanning markers CS.7 and KM19 is associated with
a genetic factor that influences postnatal female survival, providing a possible mechanism for increasing the frequency of
particular mutations in the adjacent CFTR gene.
Received: 30 January 1996 / Revised: 16 December 1996 相似文献
16.
Class I major histocompatibility complex (Mhc) cDNA clones were isolated from axolotl mRNA by polymerase chain reaction (PCR) and by screening a cDNA phage library. The
nucleotide and predicted amino acid sequences show definite similarities to the Mhc class Iα molecules of higher vertebrates.
Most of the amino acids in the peptide binding region that dock peptides at their N and C termini in mammals are conserved.
Several amino acids considered to be important for the interaction of β2-microglobulin with the Mhc α chain are also conserved in the axolotl sequence. The fact that axolotl class I A cDNAs are
ubiquitously expressed and highly polymorphic in the α1 and α2 domains suggests the classical nature of axolotl class I A
genes.
Received: 3 June 1996 / Revised: 14 October 1996 相似文献
17.
Total RNA was isolated from the diatom Cyclotella cryptica and separated into poly(A)+ and poly(A)− fractions. These fractions were subjected to in vitro translation/immunoprecipitation experiments using an antiserum directed
against the predominant light-harvesting complex of Cy. cryptica (ccry antiserum) and a heterologous antiserum raised against the light-harvesting complex of the cryptophyte Cryptomonas maculata (cmac antiserum). From translation reactions programmed with poly(A)+ RNA the ccry-antiserum immunoprecipitated polypeptides with relative molecular weights (Mr) of 27 000, 25 000, 23 000 and 21 000, while
the cmac-antiserum precipitated proteins with Mrs of 32 500 and 27 000, respectively. Subsequent cDNA synthesis and immunological
screening of the cDNA library with both antisera resulted in the isolation of six cDNA clones encoding light-harvesting subunits.
Full-length precursors were 199-210 amino acids in length and had Mrs of 20 000–23 000. The lengths of the putative signal peptides were 29 or 30 amino acids.
Pairwise comparison revealed that the similarity between the clones ranged from 54–99% on the nucleotide level and from 36–99%
at the amino acid level. In agreement with the data from the screens with the two antisera, the genes clustered into two groups.
The data provide evidence that the genes constitute a heterogeneous multigene family and that the light-harvesting system
of Cy. cryptica might be as complex as that of higher plants and green algae.
Received: 23 March 1998 / Accepted: 25 July 1998 相似文献
18.
Eight compounds exuded from young roots of black locust (Robinia pseudoacacia) were separated by two-dimensional HPTLC, by HPLC and GC, and were identified by spectroscopic methods (ultraviolet/visible
spectroscopy and mass spectrometry) as 4′,7-dihydroxyflavone, apigenin, naringenin, chrysoeriol and isoliquiritigenin. Structural
assignments were confirmed by comparison with authentic standards. The capacity to induce β-galactosidase activity in Rhizobium sp. NGR234 containing a nod box::lacZ fusion on plasmid pA27 identified these flavonoids and the chalcone as nod gene inducers. This indicates the important role of these compounds in nodulation of this legume tree.
Received: 26 July 1996 / Accepted: 9 September 1996 相似文献
19.
Chicken B-cell marker chB6 (Bu-1) is a highly glycosylated protein of unique structure 总被引:5,自引:0,他引:5
The chB6 molecule is expressed on chicken B cells throughout most of their development, as well as on some non-lymphoid cells.
It has long been used as an allotypic marker in important studies of B-cell development, though its function is unknown. We
isolated a chB6 cDNA by expression cloning and sequenced two further alleles following polymerase chain reaction amplification.
The results show that chB6 is a typical type I transmembrane protein, highly glycosylated in the extracellular region and
carrying a large intracellular region. It has no recognizable similarity to known mammalian molecules and thus represents
a unique B-cell marker. Its presence in chickens may be related to differences in the properties of B-cell development between
chickens and mammalian species. The sequences of the different alleles of this gene revealed a higher level of polymorphism
than expected. A restriction fragment length polymorphism linked to the CHB6 gene has been used to determine its location on the linkage map of the chicken genome, which will allow the definitive evaluation
of reported associations with disease resistance.
Received: 21 February 1996 / Revised: 26 March 1996 相似文献