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Home / Equine Research Bank / Dev Reprod / Specific Biological Activity of Equine Chorionic Gonadotropi...
Development & reproduction2021; 25(4); 199-211; doi: 10.12717/DR.2021.25.4.199

Specific Biological Activity of Equine Chorionic Gonadotropin (eCG) Glycosylation Sites in Cells Expressing Equine Luteinizing Hormone/CG (eLH/CG) Receptor.

Abstract: Equine chorionic gonadotropin (eCG), produced by the endometrial cups of the placenta after the first trimester, is a specific glycoprotein that displays dual luteinizing hormone (LH)-like and follicle-stimulating hormone (FSH)-like effects in non-equid species. However, in equidaes, eCG exhibits only LH-like activity. To identify the specific biological functions of glycosylated sites in eCG, we constructed the following site mutants of N- and O-linked glycosylation: eCGβ/αΔ56, substitution of α-subunit N-linked glycosylation site; eCGβ-D/α, deletion of the O-linked glycosylation sites at the β-subunit, and eCGβ-D/αΔ56, double mutant. We produced recombinant eCG (rec-eCG) proteins in Chinese hamster ovary suspension (CHO-S) cells. We examined the biological activity of rec-eCG proteins in CHO-K1 cells expressing the eLH/CG receptor and found that signal transduction activities of deglycosylated mutants remarkably decreased. The EC levels of eCGβ/αΔ56, eCGβ-D/α, and eCGβ-D/αΔ56 mutants decreased by 2.1-, 5.6-, and 3.4-fold, respectively, compared to that of wild-type eCG. The Rmax values of the mutants were 56%-80% those of wild-type eCG (141.9 nmol/10 cells). Our results indicate that the biological activity of eCG is greatly affected by the removal of N- and O-linked glycosylation sites in cells expressing eLH/CGR. These results provide important information on rec-eCG in the regulation of specific glycosylation sites and improve our understanding of the specific biological activity of rec-eCG glycosylation sites in equidaes.
© Copyright 2021 The Korean Society of Developmental Biology.
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Publication Date: 2021-12-31 PubMed ID: 35141446PubMed Central: PMC8807129DOI: 10.12717/DR.2021.25.4.199Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research explores the function of specific sugar-molecule (glycosylation) sites in equine chorionic gonadotropin (eCG), a protein produced by pregnant horses. The researchers found that removing these sites drastically reduces eCG’s biological activity, showing that these sites play a key role in regulating eCG’s performance.

Understanding the Study and its Context

  • The study focuses on equine chorionic gonadotropin (eCG), a glycoprotein produced by horse placenta after the first trimester of pregnancy. It exhibits dual activities, descending from luteinizing hormone and follicle-stimulating hormone, in non-equine species. However, in equines, eCG only showcases LH-like activity.
  • The researchers’ goal was to identify the specific biological functions of the glycosylation sites in eCG. Glycosylation sites are spots on proteins where sugar chains are attached, and they often play important roles in protein function.

The Testing Process

  • Several mutants of eCG were created, targeting N- and O-linked glycosylation sites, to explore their impact on hormone activity. The researchers created three different mutants of eCG, each with different alterations or deletions at the glycosylation sites.
  • These mutant proteins were then produced in Chinese hamster ovary suspension (CHO-S) cells. The choice of this cell line is due to its widespread use in biotechnology for protein production.
  • The researchers then examined the biological activity of these mutant proteins in another type of cell that expressed the equine luteinizing hormone receptor. This receptor would be responsible for activating the eCG.

The Results and their Implications

  • The research demonstrated that the absence of glycosylation considerably reduced the biological activity of the mutants. The levels of the substituted or deleted mutants, comparatively to the wild-type eCG, considerably dropped by specific folds.
  • The maximum response (Rmax) values of the mutants were also significantly lower than those of the wild-type eCG. This shows a decrease in performance and effectiveness of the proteins upon removal or alteration of the glycosylation sites.
  • The findings are important as they demonstrate the vital role of N- and O-linked glycosylation sites in the biological performance of eCG. This information will improve our understanding of eCG, especially its regulation and biological activity, which could have significant implications for veterinary medicine and equine reproduction in the future.

Cite This Article

APA
Byambaragchaa M, Choi SH, Joo HE, Kim SG, Kim YJ, Park GE, Kang MH, Min KS. (2021). Specific Biological Activity of Equine Chorionic Gonadotropin (eCG) Glycosylation Sites in Cells Expressing Equine Luteinizing Hormone/CG (eLH/CG) Receptor. Dev Reprod, 25(4), 199-211. https://doi.org/10.12717/DR.2021.25.4.199

Publication

Development & reproduction
ISSN: 2465-9525
NlmUniqueID: 101178352
Country: Korea (South)
Language: English
Volume: 25
Issue: 4
Pages: 199-211

Researcher Affiliations

Byambaragchaa, Munkhzaya
  • Institute of Genetic Engineering, Hankyong National University, Ansung 17579, Korea.
Choi, Seung-Hee
  • Animal Biotechnology, Hankyong National University, Ansung 17579, Korea.
Joo, Hyo-Eun
  • Dept. of Animal Life Science, Hankyong National University, Ansung 17579, Korea.
Kim, Sang-Gwon
  • Dept. of Animal Life Science, Hankyong National University, Ansung 17579, Korea.
Kim, Yean-Ji
  • Dept. of Animal Life Science, Hankyong National University, Ansung 17579, Korea.
Park, Gyeong-Eun
  • Dept. of Animal Life Science, Hankyong National University, Ansung 17579, Korea.
Kang, Myung-Hwa
  • Dept. of Food Science and Nutrition, Hoseo University, Asan 31499, Korea.
Min, Kwan-Sik
  • Institute of Genetic Engineering, Hankyong National University, Ansung 17579, Korea.
  • Animal Biotechnology, Hankyong National University, Ansung 17579, Korea.
  • Dept. of Animal Life Science, Hankyong National University, Ansung 17579, Korea.

Conflict of Interest Statement

The authors declare no potential conflict of interest.

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Citations

This article has been cited 2 times.
  1. Rodríguez MC, Mussio PE, Villarraza J, Tardivo MB, Antuña S, Fontana D, Ceaglio N, Prieto C. Physicochemical Characterization of a Recombinant eCG and Comparative Studies with PMSG Commercial Preparations. Protein J 2023 Feb;42(1):24-36.
    doi: 10.1007/s10930-023-10092-xpubmed: 36652139google scholar: lookup
  2. Byambaragchaa M, Joo HE, Kim SG, Kim YJ, Park GE, Min KS. Signal Transduction of C-Terminal Phosphorylation Regions for Equine Luteinizing Hormone/Chorionic Gonadotropin Receptor (eLH/CGR). Dev Reprod 2022 Mar;26(1):1-12.
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