scholarly journals Human mucin gene MUC4: organization of its 5′-region and polymorphism of its central tandem repeat array

1998 ◽  
Vol 332 (3) ◽  
pp. 739-748 ◽  
Author(s):  
Séverine NOLLET ◽  
Nicolas MONIAUX ◽  
Jacques MAURY ◽  
Danièle PETITPREZ ◽  
Pierre DEGAND ◽  
...  

In a previous study we isolated a partial cDNA with a tandem repeat of 48 bp, which allowed us to map a novel human mucin gene named MUC4to chromosome 3q29. Here we report the organization and sequence of the 5´-region and its junction with the tandem repeat array of MUC4. Analysis of three overlapping genomic clones allowed us to obtain a partial restriction map of MUC4 and to locate the complete 48 bp tandem repeat domain on a PstI/EcoRI genomic fragment that exhibits a very large variation in number of tandem repeats (7–19 kb). cDNA clonal extension allowed us to obtain the entire 5´ coding region of MUC4. Exon 1 consists of a 5´ untranslated region and an 82 bp fragment encoding the signal peptide. This latter shows a high degree of similarity to the signal peptide of another apomucin, ASGP-1. Exon 2 is extremely large and contains a unique sequence that is followed by the whole tandem repeat domain. It encodes only one cysteine residue, making MUC4 different from mucin genes belonging to the 11p15.5 family. Moreover, an intron downstream from the tandem repeat array consists mainly of a 15 bp tandem repeat that exhibits a polymorphism in having a variable number of tandem repeats.

MedChemComm ◽  
2016 ◽  
Vol 7 (6) ◽  
pp. 1102-1122 ◽  
Author(s):  
Shobith Rangappa ◽  
Gerard Artigas ◽  
Risho Miyoshi ◽  
Yasuhiro Yokoi ◽  
Shun Hayakawa ◽  
...  

The conformational impact of the clusteredO-glycans strongly influences recognition by antibodies of the cancer-relevant epitope in the MUC1 extracellular tandem repeat domain.


2001 ◽  
Vol 358 (3) ◽  
pp. 763-772 ◽  
Author(s):  
Fabienne ESCANDE ◽  
Jean-Pierre AUBERT ◽  
Nicole PORCHET ◽  
Marie-Pierre BUISINE

Human mucin gene MUC5AC is clustered with MUC2, MUC5B and MUC6 on chromosome 11p15.5. We report here the full length cDNA sequence upstream of the repetitive region of human MUC5AC. We have also determined the sequence of its large central tandem repeat array. The 5′-region reveals high degree of sequence similarity with MUC2 and MUC5B and codes for 1336 amino acids organized into a signal peptide, four pro-von Willebrand factor-like D domains (D1, D2, D′ and D3) and a short domain which connects to the central repetitive region. In the central region, 17 major domains have been identified. Nine code for cysteine-rich domains (Cys-domains 1–9) and exhibit high sequence similarity to the cysteine-rich domains described in the central region of MUC2 and MUC5B. Cys-domains 1–5 are interspersed by domains enriched with serine, threonine, and proline residues. Cys-domains 1–9 are interspersed by four domains (TR1–TR4) composed of various numbers of MUC5AC-type repeats. Southern-blot analyses reveal allelic variations both in length and nucleotide sequence. The length polymorphism which is due to variable numbers of tandem repeats is located in TR1 and TR4, whereas a mutation polymorphism detected with TaqI is located in Cys-domain 6. In this study, the organization of MUC5AC has been entirely elucidated showing extensive similarity to the other chromosome 11p15 MUC genes, particularly MUC5B, and providing additional arguments for common evolution from a single ancestral gene.


2020 ◽  
Vol 12 (11) ◽  
pp. 1965-1974
Author(s):  
Hanhan Xia ◽  
Wei Zhao ◽  
Yong Shi ◽  
Xiao-Ru Wang ◽  
Baosheng Wang

Abstract Short tandem repeats (STRs) contribute to structural variation in plant mitochondrial genomes, but the mechanisms underlying their formation and expansion are unclear. In this study, we detected high polymorphism in the nad7-1 region of the Pinus tabuliformis mitogenome caused by the rapid accumulation of STRs and rearrangements over a few million years ago. The STRs in nad7-1 have a 7-bp microhomology (TAG7) flanking the repeat array. We then scanned the mitogenomes of 136 seed plants to understand the role of microhomology in the formation of STR and mitogenome evolution. A total of 13,170 STRs were identified, and almost half of them were associated with microhomologies. A substantial amount (1,197) of microhomologies was long enough to mediate structural variation, and the length of microhomology is positively correlated with the length of tandem repeat unit. These results suggest that microhomology may be involved in the formation of tandem repeat via microhomology-mediated pathway, and the formation of longer duplicates required greater length of microhomology. We examined the abundance of these 1,197 microhomologies, and found 75% of them were enriched in the plant mitogenomes. Further analyses of the 400 prevalent microhomologies revealed that 175 of them showed differential enrichment between angiosperms and gymnosperms and 186 differed between angiosperms and conifers, indicating lineage-specific usage and expansion of microhomologies. Our study sheds light on the sources of structural variation in plant mitochondrial genomes and highlights the importance of microhomology in mitochondrial genome evolution.


2018 ◽  
Vol 27 (18) ◽  
pp. 3283-3292 ◽  
Author(s):  
Takeshi Saito ◽  
Satoshi Hara ◽  
Tomoko Kato ◽  
Moe Tamano ◽  
Akari Muramatsu ◽  
...  

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 10072-10072
Author(s):  
D. B. Rubinstein ◽  
R. Ziv ◽  
M. Karmely ◽  
O. Leitner ◽  
D. Wreschner

10072 Background: MUC1, a glycoprotein highly expressed in epithelial malignancies including breast, prostate, and ovarian, and on the malignant cells of multiple myeloma has generated considerable interest as a tumor marker and target for tumor killing. The most intensively studied MUC1 protein is a type I transmembrane protein (MUC1/TM) which is proteolytically cleaved soon after synthesis into α and β subunits which bind in a strong non-covalent interaction. Almost all antibodies generated to date against MUC1 recognize epitopes within the highly immunogenic tandem-repeat-array. A major shortcoming in use of such antibodies is the fact that the tandem-repeat-array-containing part of MUC1 is shed from the cell surface into the circulation. Soluble, shed MUC1 sequesters circulating anti-tandem-repeat-array antibodies, limiting their ability to reach targeted MUC1-expressing cells. Antibodies to MUC1 epitopes tethered to the cell surface would likely be more effective therapeutic agents. Despite efforts in recent years, such antibodies have remained elusive; generation of anti-cell antibodies requires characterization of cell-bound epitopes. The junction of the MUC1 α-subunit binding the membrane-tethered β-subunit provides such an epitope. Methods: By use of a novel protocol, entailing immunization with MUC1/TM cDNA and boosting with MUC1/X protein, a MUC1 isoform lacking the tandem-repeat-array, we generated monoclonal antibodies designated DMC209 which recognize the MUC1 α/β junction. Results: DMC209 is exquisitely unique for the target site; all amino acid mutations which abrogate MUC1 cleavage also abrogate DMC209 binding. Additionally, DMC209 binds the MUC1 α/β junction on cell-tethered tandem-repeat-array-containing MUC1 (MUC1/TM) on breast and ovarian cancer, and on myeloma cells. Conclusion: DMC209 is likely to have clinical application by targeting MUC1-expressing cells directly, and as an immunotoxin conjugate. Moreover, the novel high-titer immunization procedure used in generating DMC209 can be used to generate anti-MUC1 α/β junction antibodies acting as ligand and, analogously to herceptin, may have direct cytotoxic activity. No significant financial relationships to disclose.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 3034-3034
Author(s):  
M. Karmely ◽  
D. B. Rubinstein ◽  
D. H. Wreschner

3034 Background: MUC1 protein has generated considerable interest as a target for tumor killing. However, a serious shortcoming of anti-MUC1 antibodies generated to date is that they recognize epitopes within the strongly immunogenic tandem-repeat-array of the MUC1 a- chain which is released from the cell into the circulation. Soluble shed MUC1 a-chain sequesters anti-tandem-repeat-array antibodies, severely limiting their ability to reach MUC1-expressing malignant cells. Rather than target freely circulating MUC1 a-chain, we identified the junction of the MUC1 a-subunit to cell-membrane-bound MUC1 β-subunit as a preferable cell-tethered MUC1 epitope; since the site is not shed, antibodies recognizing it are more effective in targeting MUC1 expressing cells. Methods: To circumvent the immunogenicity of the a-chain tandem repeat array we formulated a novel antibody generating protocol utilizing immunization with both MUC1 cDNA and with the alternatively-spliced MUC1/X protein isoform from which the tandem repeat array is deleted. After immunization and hybridoma formation, anti- MUC1 a/β junction antibodies were selected. Results: DMC209 monoclonal antibodies uniquely specific for the MUC1 a/β junction were generated. The antibodies specifically bind the MUC1 a/β junction on full-length MUC1 expressed by breast and ovarian cancer cells, and on MUC1-positive malignant plasma cells of multiple myeloma. To demonstrate that anti-MUC1 a/β junction antibodies kill malignant cells, immunotoxin conjugates were formed with anti-MUC1 a/β junction polyclonal antibodies generated in our cDNA/protein immunization protocol and PE38, a powerful pseudomonas exotoxin. The antibody-exotoxin conjugates were potently cytocidal to MUC1-expressing malignant cells. Significantly, cell killing was abrogated by addition of soluble MUC1/X protein, highlighting that the cell-killing immunotoxin gains cell entry via the MUC1 a/β junction. Conclusions: The MUC1 a/β junction has been identified as an important cell-tethered MUC1 epitope against which highly specific antibodies can be generated capable of killing MUC1-expressing cells. These studies point to effective anti-MUC1-based immuno-therapeutic strategies. No significant financial relationships to disclose.


Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 753-762
Author(s):  
Günther E Roth ◽  
Sigrid Wattler ◽  
Hartmut Bornschein ◽  
Michael Lehmann ◽  
Günter Korge

Abstract The Drosophila melanogaster gene Sgs-1 belongs to the secretion protein genes, which are coordinately expressed in salivary glands of third instar larvae. Earlier analysis had implied that Sgs-1 is located at the 25B2-3 puff. We cloned Sgs-1 from a YAC covering 25B2-3. Despite using a variety of vectors and Escherichia coli strains, subcloning from the YAC led to deletions within the Sgs-1 coding region. Analysis of clonable and unclonable sequences revealed that Sgs-1 mainly consists of 48-bp tandem repeats encoding a threonine-rich protein. The Sgs-1 inserts from single λ clones are heterogeneous in length, indicating that repeats are eliminated. By analyzing the expression of Sgs-1/lacZ fusions in transgenic flies, cis-regulatory elements of Sgs-1 were mapped to lie within 1 kb upstream of the transcriptional start site. Band shift assays revealed binding sites for the transcription factor fork head (FKH) and the factor secretion enhancer binding protein 3 (SEBP3) at positions that are functionally relevant. FKH and SEBP3 have been shown previously to be involved in the regulation of Sgs-3 and Sgs-4. Comparison of the levels of steady state RNA and of the transcription rates for Sgs-1 and Sgs-1/lacZ reporter genes indicates that Sgs-1 RNA is 100-fold more stable than Sgs-1/lacZ RNA. This has implications for the model of how Sgs transcripts accumulate in late third instar larvae.


1998 ◽  
Vol 83 (10) ◽  
pp. 3604-3608
Author(s):  
Gisah A. Carvalho ◽  
Roy E. Weiss ◽  
Samuel Refetoff

Fourteen T4-binding globulin (TBG) variants have been identified at the gene level. They are all located in the coding region of the gene and 6 produce complete deficiency of TBG (TBG-CD). We now describe the first mutation in a noncoding region producing TBG-CD. The proband was treated for over 20 yr with L-T4 because of fatigue associated with a low concentration of serum total T4. Fifteen family members were studied showing low total T4 inherited as an X chromosome-linked trait, and affected males had undetectable TBG in serum. Sequencing of the entire coding region and promoter of the TBG gene revealed no abnormality. However, an A to G transition was found in the acceptor splice junction of intron II that produced a new HaeIII restriction site cosegregating with the TBG-CD phenotype. Sequencing exon 1 to exon 3 of TBG complementary DNA reverse transcribed from messenger RNA of skin fibroblasts from an affected male, confirmed a shift in the ag acceptor splice site. This results in the insertion of a G in exon 2 and causes a frameshift and a premature stop at codon 195. This early termination of translation predicts a truncated TBG lacking 201 amino acids.


Genetics ◽  
2000 ◽  
Vol 155 (3) ◽  
pp. 1313-1320 ◽  
Author(s):  
John S Taylor ◽  
Felix Breden

Abstract The standard slipped-strand mispairing (SSM) model for the formation of variable number tandem repeats (VNTRs) proposes that a few tandem repeats, produced by chance mutations, provide the “raw material” for VNTR expansion. However, this model is unlikely to explain the formation of VNTRs with long motifs (e.g., minisatellites), because the likelihood of a tandem repeat forming by chance decreases rapidly as the length of the repeat motif increases. Phylogenetic reconstruction of the birth of a mitochondrial (mt) DNA minisatellite in guppies suggests that VNTRs with long motifs can form as a consequence of SSM at noncontiguous repeats. VNTRs formed in this manner have motifs longer than the noncontiguous repeat originally formed by chance and are flanked by one unit of the original, noncontiguous repeat. SSM at noncontiguous repeats can therefore explain the birth of VNTRs with long motifs and the “imperfect” or “short direct” repeats frequently observed adjacent to both mtDNA and nuclear VNTRs.


1993 ◽  
Vol 105 (4) ◽  
pp. 1137-1142 ◽  
Author(s):  
C.W. Morgans ◽  
R.R. Kopito

The 89 kDa NH2-terminal domain of erythrocyte ankyrin is composed almost entirely of 22 tandem repeats of a 33 amino acid sequence and constitutes the binding site for the cytoplasmic NH2-terminal domain of the erythrocyte anion exchanger, AE1. We have developed an assay to evaluate the in vivo interaction between a fragment of ankyrin corresponding to this domain (ANK90) and two non-erythroid anion exchangers, AE2 and AE3, that share considerable structural homology with AE1. Association was assessed by co-immunoprecipitation of ANK90-anion exchanger complexes from detergent extracts of cells cotransfected with plasmids encoding the ankyrin fragment and the anion exchanger or mutants thereof. ANK90 was co-immunoprecipitated with AE1 but not with an AE1 deletion mutant lacking the cytoplasmic NH2-terminal domain. Using this assay, we show that the brain anion exchanger AE3, but not the closely related homologue, AE2, is capable of binding to ankyrin.


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