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J C Jaton

Publications and source records attributed to J C Jaton.

At least 37 records · Page 2Linked to original sources
PubMed1989

Inactivation of rabbit immunoglobulin lambda chain variable region genes by the insertion of short interspersed elements of the C family.

Two rabbit germ-line genes encoding immunoglobulin lambda light chain V regions were cloned from a rabbit genomic liver DNA library and characterized. One, V lambda 1, is separated by at least 8 kb from any other V lambda gene. The second, V lamdba 4, forms part of a three-gene cluster with two functional V lambda genes recently reported. Both V lambda 1 and V lambda 4 have structural features rendering them pseudogenes. The coding regions have frame-shift mutations which would yield defective protein products; both genes are also interrupted by the insertions of short, interspersed repetitive elements of the C family. In the V lambda 1 gene, the 369-bp insert is located upstream of the gene between the putative TATA box and the leader exon, whereas in gene V lambda 4, the 360-bp insert interrupts the FR2 at codon 48c. In addition, the sequence of the complement-determining region 3 of gene V lambda 1 is very similar to the mouse DSP2.6 sequence.

Amino Acid Sequence↗
PubMed1989

Rheumatoid factor autoantibody-binding site: a molecular analysis using monoclonal antibodies with dual anti-TNP and anti-IgG activities.

Two out of five murine IgG3 anti-trinitrophenyl (TNP) monoclonal antibodies (mAb) obtained either by immunization with TNP-keyhole limpet hemocyanin (KLH) (CB1, CB5, CB6 and 4H10) or with dinitrophenyl-lipopolysaccharide (9A6), exhibited anti-IgG rheumatoid factor (RF) activity (CB6 and 4H10). The anti-IgG activity of these two anti-TNP RF was specifically inhibited by murine IgG as well as by the hapten TNP. In order to identify the structural basis for the anti-IgG activity, the nucleotide sequences encoding the VH and VL regions were determined. By comparing the V regions of the non-RF and RF anti-TNP mAb, it was found that one anti-TNP RF antibody, CB6, shares virtually identical VL and VH regions with two anti-TNP antibodies, CB1 and CB5, but markedly differs from these in the D region. Furthermore, the light chain framework region 2 (FR2) and FR3 of non-RF mAb, CB1, CB5 and 9A6, have amino acid sequences almost identical to those claimed for anti-IgG1 RF activity (Shlomchik et al., J. Exp. Med. 1986. 164: 407). Our findings suggest, at least in the case of CB6 mAb, the involvement of CDR, but not light chain FR residues, in IgG binding.

Amino Acid Sequence↗
PubMed1988

A rabbit Ig lambda L chain C region gene encoding C21 allotopes.

Southern blot analyses of germ-line DNA obtained from rabbits expressing lambda chains of C7 and/or C21 allotypes were performed with a rabbit C lambda region-specific probe; a 12-kbp EcoRI- and a 2-kbp BamHI-hybridizing fragment were detected only in the DNA from rabbits expressing the C21 allotype. The 12-kbp EcoRI fragment was cloned and shown to contain two C lambda region-encoding genes in the same orientation. Each is preceded by a J lambda gene segment. Nonamer-12-bp spacer-heptamer recombination signal sequences were found 5' of each J lambda segment, and splicing signals were identified at the 3' ends of the J lambda segments and the 5' ends of the corresponding C lambda genes. The C lambda 5 gene, which exhibits a sequence identical with that found in several cDNA clones, is carried by the 2-kbp BamHI fragment missing from the genomic DNA of rabbits which do not express the C21 allotype. The second C lambda gene, C lambda 6, lies 3' of C lambda 5, in a 1.6-kbp BamHI fragment which is present in genomic DNAs of all tested rabbits, irrespective of their phenotype. Its sequence is identical with that found in one cDNA clone and differs from that of C lambda 5 in 17 base positions resulting in four amino acid substitutions. A fragment of a cDNA, with a J-C region sequence identical with that encoded by the J lambda 5-C lambda 5 gene pair, was subcloned into a plasmid expression vector. The resulting polypeptide product could be specifically immunoprecipitated by anti-C21 but not anti-C7 alloantisera, showing that some, if not all, C21 allotopes are encoded by the C lambda 5 gene. In contrast, the C lambda 6 gene product was not precipitable, either by anti-C7 or by anti-C21 alloantisera, although it was readily immunoprecipitated by a goat anti-rabbit lambda chain antiserum.

Amino Acid Sequence↗
PubMed1988

Rabbit secretory components of different allotypes vary in their carbohydrate content and their sites of N-linked glycosylation.

The asparagine-linked glycosylation sites in rabbit high and low Mr secretory components (SC) have been determined for the three known allotypes, t61, t62, and t63. Purified SC polypeptides were subjected to mild periodate oxidation of terminal nonreducing sugars followed by selective reduction with [3H]sodium borohydride, SC polypeptides were further proteolytically cleaved, and the 3H-labeled peptides were isolated and characterized. Both high and low Mr SCs of the three allotypes possess a common glycosylation site at the asparagine residue position 400, whereas the second site, in the amino-terminal domain of SC, was found to be variable: the t61 and t63 allotypes contained a glycosylation site at positions 70 and 90, respectively. Moreover, although the t62 allotype was found to contain a triplet acceptor site (N-X-S) at positions 90-92, analyses showed that less than 30% of the t62 allotype peptides encompassing this region were glycosylated at residue 90. Furthermore, the amino acid sequence of the t61 SC in the region of residues 69-90 varies by 8 and 10 amino acid substitutions when compared with the t62 and t63 allotype sequences, respectively. However, neither the variation in amino acid sequence nor the variation in degree or site of glycosylation measurably affected the non-covalent binding of domain 1 to dimeric IgA.

Animals↗
PubMed1988

A member of a new VH gene family encodes antibromelinized mouse red blood cell autoantibodies.

A cDNA clone encoding the variable region of the heavy chain of a BALB/c antibromelinized mouse red blood cell (BrMRBC) monoclonal antibody has been characterized. The nucleic acid sequence indicates that the variable region of the heavy chain is likely encoded by variable-VCP12, diversity-DSP 2 (5, 7 or 8) and joining-JH1 germ-line genes. An identical combination of V genes was observed for six other CBA/J and NZB anti-BrMRBC hybridomas. The BALB/c VCP12 nucleotide sequence is less than 80% homologous to members of the 10 known VH families. Moreover, the genomic restriction fragments detected under moderate stringency conditions with the radiolabeled cDNA probe did not correspond to those obtained with probes of the most homologous VH families (7183 and X24). The results indicate that the VCP12 gene defines a new VH family which we propose to designate VH11. The observation of 1, 2 or 3 genomic restriction fragments at the most, with mice bearing the Igh-Vd or j, Igh-Va or b or Igh-Vc haplotypes, suggests the existence of a few VCP12-related genes.

Animals↗
PubMed1988

Detection of the major epitopes of human protamine P1 recognized by rabbit and mouse antibodies.

The characterization of the major antigenic determinants present in human protamine P1 has been carried out by the use of specific rabbit polyclonal and mouse monoclonal antisera raised against protamine P1. This basic protein, the full amino acid sequence of which has been determined here, has been cleaved by cyanogen bromide and/or by pepsin to generate a discrete number of peptides. These have been purified, characterized by partial amino acid sequencing and used for the determination of their antigenic reactivities with antisera to native protamine P1. Both rabbit polyclonal and mouse monoclonal antibodies were able to recognize the NH2-terminal CNBr peptide encompassing residues 1-36 to the same extent as the intact protamine. A minor epitope present on the COOH-terminal peptide 37-50 could be detected only with the polyclonal rabbit antisera. Attempts to further cleave the P1 molecule in order to isolate peptides shorter than fragments 1-36 whilst retaining full antigenic reactivities, were unsuccessful. This suggests that the epitopes in P1 are conformation-dependent and located for the most part on the amino-terminal half of the molecule, which comprises the characteristic central arginine cluster. The implication of these findings for the studies of the specificities of autoantibodies in sera from infertile and vasectomized individuals is discussed.

Amino Acid Sequence↗
PubMed1987

Rabbit secretory components: identification of a third allotype, t63.

A third allotype of rabbit secretory component has been identified. The allotype previously referred to as t62 by our laboratory can now be subdivided into two allotypes, t62 and t63, with alloantisera capable of discriminating between the two. Results of family studies are consistent with a three allele system (t61, t62 and t63) at the t-locus. By SDS PAGE, electrophoretic mobilities of the multiple SC bands for each of the three allotypes are characteristic of the allotype; the apparent molecular sizes of the bands of the t62 allotype are 2 to 3 kDa lower than those for the t61 allotype. The banding patterns of the t61 and t63, although similar, are not identical to each other. Results of serologic cross-reaction studies and of tryptic peptide mapping studies suggest multiple structural differences between the allotypes as well as a closer relationship between t62 and t63 than between either of these allotypes and t61.

Alleles↗
PubMed1987

Structural variability of rabbit secretory components. Allotype-associated differences in the third, fourth, and fifth domains.

We have previously shown (Frutiger, S., Hughes, G. J., Hanly, W. C., Kingzette, M., and Jaton, J.-C. (1986) J. Biol. Chem. 261, 16673-16681) that limited tryptic digestion of the high Mr form of rabbit secretory component of allotypes t61, t62, and t63 generates two major fragments, the NH2-terminal domain and a 40-kDa fragment encompassing domains 3, 4, and 5. Similarly, from the low Mr form of secretory component, (SC) the NH2-terminal domain, together with a 30-kDa fragment containing domains 4 and 5, were released. These fragments were used as inhibitors in a sensitive competitive binding radioimmunoassay with noncross-reactive rabbit alloantisera to study the distribution and localization of the major allotype-specific allotopes within the SC polypeptide. The 40-kDa fragments were shown to inhibit the 125I-labeled intact SC/anti-SC allotype reaction to the extent of 90%, i.e. nearly as well as the intact homologous high Mr SC form. In contrast, the NH2-terminal fragments (domain 1) were not inhibitory. The low Mr SC of each allotype was less inhibitory on a molar basis than the homologous high Mr SC polypeptide, an observation compatible with the deletion of domains 2 and 3 in the smaller polypeptide (Deitcher, D. L., and Mostov, K. E. (1986) Mol. Cell. Biol. 6, 2712-2715; Frutiger, S., Hughes, G. J., Fonck, Ch., and Jaton, J.-C. (1987) J. Biol. Chem. 262, 1712-1715). The structural correlates of the allotypic specificities were evaluated by comparative peptide mapping of the 40-kDa fragments (allotypes t61, t62, and t63). The data suggest that the t61 allotype structure differs significantly from the t62 and t63 structures, the latter two being much more related to each other than to t61. These findings are in full agreement with the serological data. The inhibition results suggest that the major allotype-specific, noncross-reactive allotopes of SC are distributed throughout domains 3, 4, and 5, even though domain 4 appears to be more conserved than domains 3 and 5 between the allotypes t61 and t63. Seven amino acid substitutions between t61 and t63 have been detected within domains 3, 4, and 5.

Amino Acid Sequence↗
PubMed1987

cDNA clones encoding rabbit immunoglobulin lambda chains. Evidence for length variation of the third hypervariable region and for a novel constant region.

Five cDNA clones designated pDH2, pDH8, pDH9, pDH31 and pDH101 encoding rabbit immunoglobulin lambda light chain sequences have been characterized. Comparison of the V lambda sequences suggests that, in addition to an increased divergence in all of the complementarity-determining regions (CDRs), variable-region diversity is amplified by the length heterogeneity of the CDR3, at the V lambda-J lambda junction. An insertion of four codons at positions 48a-d has been noted in three cDNA sequences. This insert, not found in lambda nor kappa light chains of other species, has a variable sequence, suggesting its possible implication in expanding variability of the CDR2. One of the cDNA clones was shown to encode a novel C lambda region which differs by four amino acid substitutions from the C lambda region common to all the other clones. Thus, the rabbit can use two different C lambda genes, which might correlate with the expression of the two known allotypes of lambda chains, C7 and C21. Southern blotting experiments indicate a small number of germ-line V lambda genes and the cDNA nucleotide sequence data reported here suggest that several of these genes can be expressed. The possibility of at least two V-J-C gene clusters is discussed.

Alleles↗
PubMed1987

Nucleotide sequence of a cDNA clone encoding a rabbit immunoglobulin-lambda light chain: the V lambda region differs markedly from that of other species.

A cDNA clone (pDH7) has been isolated which encodes the entire leader peptide and variable (V) region and most of the constant (C) region of a rabbit lambda-light chain. Although similar to amino acid sequences derived from fragments of isolated lambda-chains from several Basilea rabbits, differences in the first framework region (FR1) suggest that at least two germ-line V lambda genes are expressed. There are major differences between rabbit V lambda sequences and light chains of other species: in particular, rabbit lambda-chains have an additional four amino acids in the vicinity of the FR2-CDR2 junction. The same region also has significant homology with the human D2 germ-line mini-gene sequence, especially with a 14-nucleotide sequence previously shown to be homologous to human and rabbit heavy chain CDR2 sequences. Similar homologies in other heavy and light chain sequences suggest that D-gene segments may be derived from VH genes, perhaps by transposition. The framework regions of the rabbit lambda-chain encoded by clone pDH7 show the greatest homologies with those of human kappa- and lambda-sequences (46 to 54% homology), with that of chicken sequence (55%), and least with murine V lambda sequences (40%).

Amino Acid Sequence↗
PubMed1987

High and low molecular weight rabbit secretory components. Evidence for the deletion of the second and third domains in the smaller polypeptide.

Rabbit secretory components exist in two forms which differ in apparent mass by about 25 kDa. Each of these two forms were reduced, carboxymethylated, and extensively digested with trypsin. The resulting peptides were purified by reverse-phase high performance liquid chromatography and characterized by NH2- and COOH-terminal sequence determination and/or amino acid analysis. They were aligned with the protein sequence predicted from the cDNA nucleotide sequence encoding the rabbit poly(Ig) receptor (Mostov, K. E., Friedlander, M., and Blobel, G. (1984) Nature 308, 37-43). All peptides belonging to the fourth and fifth domains except one (positions 488-496) were accounted for in both forms. In addition, limited tryptic proteolysis of the native low Mr secretory components produced the intact 18-kDa NH2-terminal domain (positions 1-117) and the 30-kDa fragment encompassing the fourth and fifth domains. These results suggest that the smaller polypeptide derives from the larger secretory component form by the deletion of the second and third domains.

Amino Acid Sequence↗
PubMed1987

Novel V genes encode virtually identical variable regions of six murine monoclonal anti-bromelain-treated red blood cell autoantibodies.

The variable (V) region sequences of six immunoglobulin M (IgM, kappa) monoclonal autoantibodies that recognize bromelinized isologous red blood cells, obtained by fusions of peritoneal cells from NZB or CBA/J nonimmunized mice with BALB/c myeloma cells, were determined by direct mRNA sequencing. The V regions of the light chains (VL) are almost identical with one another, as are the V regions of the heavy chains (VH), which, however, differ by six linked-base substitutions, depending on the strain of mice producing the autoantibodies. Such variations may reflect allelic differences. The VH segments determined have no obvious correspondence to any VH genes identified so far. They may belong to the small VH group 4, where 73% homology, at the most, can be calculated at the protein level for codons 1 to 94. Alternatively, the VH regions may be members of a new group of VH sequences not previously found. The V kappa regions appear closely homologous to members of the V kappa-9 subgroup of myeloma proteins of unknown antigen-binding specificity. The joining segments, J kappa and JH, used by the autoantibodies investigated, originate from the J kappa 2 and JH1 germ-line gene segments, respectively. The nine base-long diversity segments, D, derive from one member of the germ-line D gene SP2 family.

Animals↗
PubMed1986

The amino-terminal domain of rabbit secretory component is responsible for noncovalent binding to immunoglobulin A dimers.

Rabbit secretory components (SC) constitute a family of markedly heterogeneous glycoproteins which are released in the secretions as free SC or as SC bound to polymeric immunoglobulins. The aim of this work was to determine the region of the SC polypeptides which is involved in IgA binding. The high and the low Mr forms of free SC (or IgA-dissociated bound SC) and the native secretory IgA complex were subjected to limited tryptic digestion. Chemically characterized peptides ranging in apparent size from 15 to 20 kDa, depending upon the allotype, were shown to be necessary and sufficient for efficient noncovalent binding to IgA dimers (subclass g). These fragments encompass the amino-terminal first domain of SC, i.e. residues 1-126, when aligned with the predicted amino acid sequence from a cDNA clone encoding the rabbit polymeric Ig receptor (Mostov, K.E., Friedlander, M., and Blobel, G. (1984) Nature 308, 37-43). The high and the low Mr forms of SC exhibited the same relative affinity for IgA dimers, suggesting that the postulated internal deletion in the smaller polypeptide (Kühn, L. C., Kocher, H.-P., Hanly, W.C., Cook, L., Jaton, J.-C., and Kraehenbuhl, J.-P. (1983) J. Biol. Chem. 258, 6653-6659) does not impair the IgA dimer recognition function.

Amino Acid Sequence↗
PubMed1986

Characterization of four constant region genes of rabbit immunoglobulin-lambda chains.

A cDNA plasmid insert encoding the constant (C) region of a rabbit immunoglobulin-lambda light chain was used as a probe for screening a rabbit liver genomic DNA cosmid library. This allowed the isolation and identification of four distinct C lambda genes, designated C lambda 1, C lambda 2, C lambda 3, and C lambda 4, which were shown to be widely separated from each other along chromosomal DNA. Their nucleotide sequences have been determined. No in-frame termination codons were found within the coding regions. The C lambda 1, C lambda 2, and C lambda 3 sequences are quite similar to each other, but share less homology with the C lambda 4 gene or the cDNA-C lambda sequence used as a probe. The C lambda gene coding for the cDNA sequence was not isolated. Translation of the C lambda 1, C lambda 2, and C lambda 3 sequences predicts a Cys-Pro carboxy-terminal amino acid sequence, as found so far only for horse lambda-chains. Compared to the other rabbit C lambda genes, the C lambda 3 sequence exhibits two deletions, one of 9 bp, the other of 3 bp. The latter occurs at the same position as in the mouse C lambda 2 and C lambda 3 genes. These two deletions are located in the loops between anti-parallel beta-pleated sheets of the C lambda domain. When the C lambda nucleotide sequences from man, mouse, and rabbit are compared, there is less divergence within the same species than for interspecies comparisons. Possible genetic implications of this finding are discussed.

Amino Acid Sequence↗
PubMed1985

Monoclonal autoantibodies against mouse red blood cells: a family of structurally restricted molecules.

Cultured mouse peritoneal cells from unstimulated mice developed plaque-forming activity against isologous bromelain-treated erythrocytes. Several IgM monoclonal autoantibodies obtained by fusion of peritoneal cells from NZB or CBA origin with BALB/c myeloma cells were purified by affinity chromatography on trimethyl ammonium (TMA) column on the basis of their cross-reactivity with TMA, phosphorylcholine (PC) or choline haptens. Binding affinity for PC hapten was of the order of 10(3) M-1. Idiotypic studies with a polyclonal rabbit anti-idiotypic reagent revealed strong cross-reactions with all hybridoma autoantibodies thus far tested. In addition, the rabbit anti-idiotypic serum detected idiotypes or cross-reactive idiotypes in the sera of NZB and CBA as well as BALB/c mice. N-terminal amino acid sequence analyses of three hybridoma autoantibodies from NZB mice and one from CBA mice were carried out. The sequences of the first 32 residues of the four heavy chains showed that three were identical while one had one amino acid interchange; they belong to the VHIII-subgroup. The light chains were identical in the first 35 residues with the exception of a substitution at position 3 in two light chains and are members of the VK-9-subgroup. These results entirely support the idiotypic data. These monoclonal autoantibodies from NZB and CBA mice although isolated and eluted from PC-related haptens do not have any apparent structural nor idiotypic relationship to PC-specific antibodies. Idiotypic and V-region N-terminal sequence data suggest that these autoantibodies constitute a highly restricted family of molecules likely to be encoded by unique germ-line genes which may be expressed as such or as somatic variants in different mouse strains.

Aging↗
PubMed1984

Nucleotide sequence of a cDNA encoding the constant region of a rabbit immunoglobulin light chain of the lambda type.

A cDNA library has been constructed in the plasmid pBR322 using as template 12 S poly(A)-RNA isolated from spleen cells of a hyperimmunized Basilea rabbit. One of these cDNA-containing clones was used to determine the nucleotide sequence coding for the lambda light chain constant (C) region. The deduced amino acid sequence of this cDNA was found in good agreement with a Basilea rabbit C lambda region amino acid sequence previously determined. The nucleotide sequence of the rabbit C lambda-coding region was compared with man, mouse and chicken C lambda sequences and showed 78%, 72% and 66% homology, respectively. Southern blot hybridization analyses of liver DNA from various rabbits were carried out. The comparison of the restriction patterns suggests that a few C lambda-related genes occur in the rabbit genome. In addition, discrete differences in the restriction patterns may exist between rabbits of different genetic backgrounds.

Animals↗
PubMed1983

Structural and genetic heterogeneity of the receptor mediating translocation of immunoglobulin A dimer antibodies across epithelia in the rabbit.

Secretory component (SC), synthesized as a transmembrane protein, acts as the receptor that binds IgA dimers and mediates their transepithelial transport. Cleavage of the receptor (membrane SC) apparently occurs during transport and a fragment, the secreted form, is generated, which remains tightly bound to the IgA dimer. In the rabbit, variation in the size of membrane SC is observed with both a high and a low molecular weight family, each composed either of two or of four distinct polypeptides depending on the individual rabbit. The same degree of size heterogeneity is observed for secreted SC. Part of this size heterogeneity is related to genetic polymorphism. The milk of individual rabbits typed with anti-SC-allotype sera reveals three different banding patterns. The simplest pattern, found in t61/t61 and t62/t62 homozygotes, consists of an upper and a lower doublet. Since each band of these two doublets in the t62 allotype migrates slightly faster than its counterpart in the t61 allotype, a composite pattern is observed in the heterozygotes (t61/t62). Within a given allotypic group, all SC polypeptide chains expressed the identical allotypic specificity. The 2000 to 4000 difference in molecular weight between the two forms of a doublet probably reflects differences in the number of glycosylated asparagine residues, since individual bands of a doublet show identical peptide maps. High and low molecular weight families are also structurally related to each other as shown by one-dimensional peptide maps and identical NH2- and COOH-terminal amino acid sequences. These results indicate that the 25-kDa size difference between SC from the high and low molecular weight families reflects an intramolecular deletion.

Amino Acid Sequence↗