Topic
Choriolysin H
About: Choriolysin H is a research topic. Over the lifetime, 6 publications have been published within this topic receiving 102 citations.
Papers
TL;DR: It was found that the hatching gland cells of zebrafish and masu salmon originated from the anterior end of the hypoblast, the Polster, as did those of medaka by in situ hybridization, and it was clarified that difference in the final location of hatching glands cells among these species resulted from the difference inThe migratory route of the hatch gland cells after thePolster region.
Abstract: Two constituent proteases of the hatching enzyme of the medaka (Oryzias latipes), choriolysin H (HCE) and choriolysin L (LCE), belong to the astacin protease family. Astacin family proteases have a consensus amino acid sequence of HExxHxxGFxHExxRxDR motif in their active site region. In addition, HCE and LCE have a consensus sequence, SIMHYGR, in the downstream of the active site. Oligonucleotide primers were constructed that corresponded to the above-mentioned amino acid sequences and polymerase chain reactions were performed in zebrafish (Brachydanio rerio) and masu salmon (Oncorynchus masou) embryos. Using the amplified fragments as probes, two full-length cDNA were isolated from each cDNA library of the zebrafish and the masu salmon. The predicted amino acid sequences of the cDNA were similar to that of the medaka enzymes, more similar to HCE than to LCE, and it was conjectured that hatching enzymes of zebrafish and masu salmon also belonged to the astacin protease family. The final location of hatching gland cells in the three fish species: medaka, zebrafish and masu salmon, is different. The hatching gland cells of medaka are finally located in the epithelium of the pharyngeal cavity, those of zebrafish are in the epidermis of the yolk sac, and those of masu salmon are both in the epithelium of the pharyngeal cavity and the lateral epidermis of the head. However, in the present study, it was found that the hatching gland cells of zebrafish and masu salmon originated from the anterior end of the hypoblast, the Polster, as did those of medaka by in situ hybridization. It was clarified, therefore, that such difference in the final location of hatching gland cells among these species resulted from the difference in the migratory route of the hatching gland cells after the Polster region.
83 citations
TL;DR: In the present study, the genes for HCE and LCE were isolated from the genomic library constructed from DNA of the inbred drR strain fish and there was a marked difference in their gene organization.
Abstract: The hatching enzyme of the teleost, Oryzias latipes, is composed of two proteases, high choriolytic enzyme (choriolysin H, HCE) and low choriolytic enzyme (choriolysin L, LCE), which are similar in some enzymological characteristics and protein structure (55% identity in amino acid sequence) and belong to the astacin family. Two isoforms of HCE are detected. In the present study, the genes for HCE and LCE were isolated from the genomic library constructed from DNA of the inbred drR strain fish. In contrast to the close similarity of the enzymes, there was a marked difference in their gene organization. The LCE gene was a single copy gene and composed of eight exons interrupted by seven introns. The HCE genes were multicopy genes and lacked introns. In the haploid genome of the drR strain fish, there are eight HCE genes, seven of which were cloned. Each HCE gene was identified as that for either of the two isoforms of HCE. 5′ flanking regions of the LCE gene and the HCE genes had consensus TATA box sequences, but not CAT box nor GC box sequences. The big difference in the exon-intron organization between the HCE genes and the LCE gene is discussed from an evolutionary viewpoint.
30 citations
1 Jan 2011
TL;DR: Analysis showed that ZHE1 and HCE maintain the character of an ancestral hatching enzyme, swelling of the egg envelope, and that LCE acquires a new function, the complete digestion of the HCE-swollen egg envelope.
Abstract: At the hatching of medaka embryos, the egg envelope is completely solubilized by two proteases, high choriolytic enzyme (HCE, or choriolysin H) and low choriolytic enzyme (LCE, or choriolysin L). HCE causes the egg envelope to swell, and LCE solubilizes the swollen envelope. Molecular phylogenetic analysis has shown that the hatching enzyme was originally composed of a single enzyme, and during evolution, the hatching system consisting of two types of enzymes was established by duplication and diversification of the genes. We compared the egg envelope digestion mechanism between zebrafish having the single enzyme, ZHE1, and medaka having the two enzymes, HCE and LCE. The digestion manner of ZHE1 was highly homologous to that of HCE with respect to swelling of the egg envelope. The cross-species digestion experiment using enzymes and substrates of both zebrafish and medaka revealed that the substrate specificity of ZHE1 is quite similar to that of HCE, whereas the specificity of LCE is different from those of ZHE1 and HCE. Further analysis showed that ZHE1 and HCE maintain the character of an ancestral hatching enzyme, swelling of the egg envelope, and that LCE acquires a new function, the complete digestion of the HCE-swollen egg envelope. Considering several factors such as the origin of egg envelope protein and the spawning environment of eggs, we discuss a co-evolutionary aspect of the hatching enzyme and egg envelope.
3 citations
[...]
TL;DR: Choriolysin L as mentioned in this paper is a preproenzyme that is co-localized with choriolyin H in the secretory granules of the hatching gland cells that are located in the inner wall of the pharyngeal cavity of pre-hatching medaka embryos.
Abstract: Publisher Summary
This chapter elaborates the activity, specificity and structural chemistry of choriolysin L. Choriolysin L displays very low choriolytic activity when examined by the turbidimetric method. It hardly digests the intact inner layer of egg envelope, but efficiently digests the swollen inner layer of egg envelope prepared by a limited digestion by choriolysin H. The specificity of choriolysin L is 8,000 and 100,000 times greater than those of trypsin and thermolysin, respectively. The hatching of medaka embryos results from a two-step digestion of the two enzymes; choriolysin H swells the inner layer of egg envelope by limited digestion, and choriolysin L solubilizes the swollen part of it completely. Choriolysin L also hydrolyzes casein and some synthetic substrates such as Suc-Leu-Leu-Val-Tyr-fNHMec . The pH optimum is about 8.6 for caseinolytic activity. Choriolysin L is a single-chain protein of about 25.5 kDa and pi 9.8. The enzyme is synthesized as a preproenzyme and the mature enzyme consists of 200 amino acids. Choriolysin L is colocalized with choriolysin H in the secretory granules of the hatching gland cells that are located in the inner wall of the pharyngeal cavity of prehatching medaka embryos.
1 citations
[...]
TL;DR: Choriolysin H as discussed by the authors hydrolyzes the inner layer of the egg envelope and releases unique proline-rich polypeptides from it, which contain zinc, calcium and magnesium as revealed by metal analysis.
Abstract: Publisher Summary
This chapter discusses the activity, specificity and structural chemistry of choriolysin H. Choriolysin H hydrolyzes the inner layer of egg envelope and releases unique proline-rich polypeptides from it. As a result of hydrolysis by choriolysin H, the inner layer of egg envelope is swollen. The released polypeptides consist of repeats of Pro-Xaa-Yaa, mainly Pro-Glu-Yaa, which are present in ZI-1,2, one of the major subunit proteins of the egg envelope. The pH optimum is about 8.0 and 8.7 for caseinolytic activity and choriolytic activity, respectively. Both activities are inhibited by EDTA at a concentration of ImM, but are not inhibited by DFP, iodoacetamide or iodoacetic acid. The enzyme contains zinc, calcium and magnesium as revealed by metal analysis. Choriolysin H tends to bind tightly to the egg envelope. One of the antichoriolysin H monoclonal antibodies does not affect caseinolytic activity, but inhibits both choriolytic activity and binding to the egg envelope. The choriolysin H genes are multicopy genes and lack introns. Six of seven HCE genes cloned are situated in a cluster and arranged in tandem. A putative promoter region of each gene contains a TATA box sequence, but neither a CAT box nor GC box sequences.
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2013 | 1 |
| 2011 | 1 |
| 2004 | 2 |
| 1997 | 1 |
| 1996 | 1 |