scholarly journals The human E48 antigen, highly homologous to the murine Ly-6 antigen ThB, is a GPI-anchored molecule apparently involved in keratinocyte cell-cell adhesion.

1995 ◽  
Vol 129 (6) ◽  
pp. 1677-1689 ◽  
Author(s):  
R H Brakenhoff ◽  
M Gerretsen ◽  
E M Knippels ◽  
M van Dijk ◽  
H van Essen ◽  
...  

The E48 antigen, a putative human homologue of the 20-kD protein present in desmosomal preparations of bovine muzzle, and formerly called desmoglein III (dg4), is a promising target antigen for antibody-based therapy of squamous cell carcinoma in man. To anticipate the effect of high antibody dose treatment, and to evaluate the possible biological involvement of the antigen in carcinogenesis, we set out to molecularly characterize the antigen. A cDNA clone encoding the E48 antigen was isolated by expression cloning in COS cells. Sequence analysis revealed that the clone contained an open reading frame of 128 amino acids, encoding a core protein of 13,286 kD. Database searching showed that the E48 antigen has a high level of sequence similarity with the mouse ThB antigen, a member of the Ly-6 antigen family. Phosphatidylinositol-specific (PI-specific) phospholipase-C treatment indicated that the E48 antigen is glycosylphosphatidylinositol-anchored (GPI-anchored) to the plasma membrane. The gene encoding the E48 antigen is a single copy gene, located on human chromosome 8 in the 8q24-qter region. The expression of the gene is confined to keratinocytes and squamous tumor cells. The putative mouse homologue, the ThB antigen, originally identified as an antigen on cells of the lymphocyte lineage, was shown to be highly expressed in squamous mouse epithelia. Moreover, the ThB expression level is in keratinocytes, in contrast to that in lymphocytes, not mouse strain related. Transfection of mouse SV40-polyoma transformed mouse NIH/3T3 cells with the E48 cDNA confirmed that the antigen is likely to be involved in cell-cell adhesion.

1989 ◽  
Vol 9 (3) ◽  
pp. 935-945
Author(s):  
L A Johnston ◽  
M A Kotarski ◽  
D J Jerry ◽  
L P Kozak

While studying the organization of the mouse glycerol-phosphate dehydrogenase gene (Gdc-1 on chromosome 15), we identified a novel transcriptional unit located only 3.4 kilobases (kb) upstream of the 5' end of the Gdc-1 gene. This gene has been provisionally named D15Kz1. The unusual proximity of these two genes led us to investigate the pattern of expression and sequence characteristics of the new gene for comparison with those of Gdc-1. D15Kz1 was found to have transcripts of 3.2 and 3.4 kb in length. The 3.4-kb transcript was expressed at low levels in all tissues examined, whereas the 3.2-kb transcript was detected only in the cerebral cortex and the brown fat. D15Kz1 and Gdc-1 are not coordinately regulated, as evidenced by the characteristics of their expression in several tissues and in differentiating 3T3-F442A adipocyte cultures. A cDNA sequence of 3,105 bases isolated from an embryonal carcinoma lambda gt10 cDNA library had a large open reading frame of 461 amino acids at one end followed by 1.6 kb of sequence with multiple stop codons. Algorithms used to search the protein and nucleic acid data bases detected no significant sequence similarity to any other protein or gene. Southern blot analysis of genomic DNA using the D15Kz1 cDNA as a probe indicated that D15Kz1 is a single-copy gene in the mouse genome and that it is conserved in humans, rats, and chickens. This conservation of gene sequences suggests that D15Kz1 encodes a protein with an important cellular function.


1992 ◽  
Vol 3 (4) ◽  
pp. 403-414 ◽  
Author(s):  
L C Smith ◽  
R J Britten ◽  
E H Davidson

SpCoel1 is a single copy gene that is specifically expressed in most of the coelomocytes of the adult purple sea urchin, Strongylocentrotus purpuratus. The 4-kb transcript from this gene has a relatively short (426 nucleotide) open reading frame (ORF) with long 3' and 5' untranslated regions. The ORF encodes a protein that has strong amino acid sequence similarity to profilins from yeast to mammals. Transcript titrations of SpCoel1 show significant increases per coelomocyte in animals that have been physiologically challenged. Increases in transcript levels are of similar magnitudes between animals receiving different treatments, such as injuries from needle punctures or from injections of foreign cells. The evidence presented here implies a molecular mechanism by which this lower deuterostome defense system responds to external insult, viz that an external "injury signal" activates a signal transduction system, which in turn mediates the alterations in cytoskeletal state that are required for coelomocyte activation.


1990 ◽  
Vol 10 (6) ◽  
pp. 3067-3077
Author(s):  
P D Friesen ◽  
M S Nissen

A single copy of the retrotransposon TED, from the moth Trichoplusia ni (a lepidopteran noctuid), was identified within the DNA genome of the baculovirus Autographa californica nuclear polyhedrosis virus. Determination of the complete nucleotide sequence (7,510 base pairs) of the integrated copy indicated that TED belongs to the family of retrotransposons that includes Drosophila melanogaster elements 17.6 and gypsy and thus represents the first nondipteran member of this invertebrate group to be identified. The internal portion of TED, flanked by long terminal repeats (LTRs), is composed of three long open reading frames comparable in size and location to the gag, pol, and env genes of the vertebrate retroviruses. Sequence similarity with the dipteran elements was the highest within individual domains of TED open reading frame 2 (pol region) that are also conserved among the retroviruses and encode protease, reverse transcriptase, and integrase functions, respectively. Mapping the 5' and 3' termini of TED RNAs indicated that the LTRs have a retroviral U3-R-U5 structural organization that is capable of directing the synthesis of transcripts that represent potential substrates for reverse transcription and intermediates in transposition. Abundant RNAs were also initiated from a site within the 5' LTR that matches the consensus motif for the promoter of late, hyperexpressed baculovirus genes. The presence of this viruslike promoter within TED and its subsequent activation only after integration within the viral genome suggest a possible symbiotic relationship with the baculovirus that could extend transposon host range.


1989 ◽  
Vol 9 (3) ◽  
pp. 935-945 ◽  
Author(s):  
L A Johnston ◽  
M A Kotarski ◽  
D J Jerry ◽  
L P Kozak

While studying the organization of the mouse glycerol-phosphate dehydrogenase gene (Gdc-1 on chromosome 15), we identified a novel transcriptional unit located only 3.4 kilobases (kb) upstream of the 5' end of the Gdc-1 gene. This gene has been provisionally named D15Kz1. The unusual proximity of these two genes led us to investigate the pattern of expression and sequence characteristics of the new gene for comparison with those of Gdc-1. D15Kz1 was found to have transcripts of 3.2 and 3.4 kb in length. The 3.4-kb transcript was expressed at low levels in all tissues examined, whereas the 3.2-kb transcript was detected only in the cerebral cortex and the brown fat. D15Kz1 and Gdc-1 are not coordinately regulated, as evidenced by the characteristics of their expression in several tissues and in differentiating 3T3-F442A adipocyte cultures. A cDNA sequence of 3,105 bases isolated from an embryonal carcinoma lambda gt10 cDNA library had a large open reading frame of 461 amino acids at one end followed by 1.6 kb of sequence with multiple stop codons. Algorithms used to search the protein and nucleic acid data bases detected no significant sequence similarity to any other protein or gene. Southern blot analysis of genomic DNA using the D15Kz1 cDNA as a probe indicated that D15Kz1 is a single-copy gene in the mouse genome and that it is conserved in humans, rats, and chickens. This conservation of gene sequences suggests that D15Kz1 encodes a protein with an important cellular function.


1990 ◽  
Vol 10 (6) ◽  
pp. 3067-3077 ◽  
Author(s):  
P D Friesen ◽  
M S Nissen

A single copy of the retrotransposon TED, from the moth Trichoplusia ni (a lepidopteran noctuid), was identified within the DNA genome of the baculovirus Autographa californica nuclear polyhedrosis virus. Determination of the complete nucleotide sequence (7,510 base pairs) of the integrated copy indicated that TED belongs to the family of retrotransposons that includes Drosophila melanogaster elements 17.6 and gypsy and thus represents the first nondipteran member of this invertebrate group to be identified. The internal portion of TED, flanked by long terminal repeats (LTRs), is composed of three long open reading frames comparable in size and location to the gag, pol, and env genes of the vertebrate retroviruses. Sequence similarity with the dipteran elements was the highest within individual domains of TED open reading frame 2 (pol region) that are also conserved among the retroviruses and encode protease, reverse transcriptase, and integrase functions, respectively. Mapping the 5' and 3' termini of TED RNAs indicated that the LTRs have a retroviral U3-R-U5 structural organization that is capable of directing the synthesis of transcripts that represent potential substrates for reverse transcription and intermediates in transposition. Abundant RNAs were also initiated from a site within the 5' LTR that matches the consensus motif for the promoter of late, hyperexpressed baculovirus genes. The presence of this viruslike promoter within TED and its subsequent activation only after integration within the viral genome suggest a possible symbiotic relationship with the baculovirus that could extend transposon host range.


2005 ◽  
Vol 173 (4S) ◽  
pp. 170-170
Author(s):  
Maxine G. Tran ◽  
Miguel A. Esteban ◽  
Peter D. Hill ◽  
Ashish Chandra ◽  
Tim S. O'Brien ◽  
...  

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