Background: Testis-specific chaperone calmegin is required for the generation of normal spermatozoa. Calmegin is known to be a homologue of endoplasmic reticulum (ER) residing lectin chaperone calnexin. Although functional similarity between calnexin and calmegin has been predicted, detailed information concerned with substrate recognition by calmegin, such as glycan specificity, chaperone function and binding affinity, are obscure.
Methods: In this study, biochemical properties of calmegin and calnexin were compared using synthetic glycans and glycosylated or non-glycosylated proteins as substrates.
Results: Whereas their amino acid sequences are quite similar to each other, a certain difference in secondary structures was indicated by circular dichroism (CD) spectrum. While both of them inhibited protein heat-aggregation to a similar extent, calnexin exhibited a higher ability to facilitate protein folding. Similarly to calnexin, calmegin preferentially recognizes monoglucosylated glycans such as Glc1Man9GlcNAc2 (G1M9). While the surface hydrophobicity of calmegin was higher than that of calnexin, calnexin showed stronger binding to substrate. We reasoned that lectin activity, in addition to hydrophobic interaction, contributes to this strong affinity between calnexin and substrate.
Conclusions: Although their similarity in carbohydrate binding specificities is high, there seems to be some differences in the mode of substrate recognition between calmegin and calnexin.
General Significance: Properties of calmegin as a lectin-chaperone were revealed in comparison with calnexin.
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http://dx.doi.org/10.1016/j.bbagen.2014.04.012 | DOI Listing |
Cancers (Basel)
January 2023
Department of Pathology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary.
( corepressor)-rearranged sarcomas (BRSs) are a heterogeneous group of sarcomas previously classified as part of the group of "atypical Ewing" or "Ewing-like" sarcomas, without the prototypical gene translocation. Due to their similar morphology and histopathological features, diagnosis is challenging. The most common genetic aberrations are fusion and internal tandem duplication (ITD).
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January 2021
Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Inuyama, Aichi, 484-8506, Japan.
Non-human primates are our closest relatives and therefore offer valuable comparative models for human evolutionary studies and biomedical research. As such, Japanese macaques (Macaca fuscata) have contributed to the advancement of primatology in both field and laboratory settings. Specifically, Japanese macaques serve as an excellent model for investigating postnatal development and seasonal breeding in primates because of their relatively prolonged juvenile period and distinct seasonal breeding activity in adulthood.
View Article and Find Full Text PDFHypertension
February 2020
From the Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan (K.I., K.O., H.O., K.K., G.N., Y.Y., R.B., N.H., M.Y.).
The endoplasmic reticulum (ER) plays a pivotal role in syntheses of proteins and steroid hormones and regulation of intracellular Ca level. We aimed to investigate ER-associated genes in aldosterone-producing adenomas (APAs) and clarify their effect on aldosterone production. Microarray analysis targeting 288 ER-associated genes was conducted using nonfunctioning adrenocortical adenomas (n=5) and APAs (n=19).
View Article and Find Full Text PDFHypertension
February 2020
From the Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, Germany; and Division of Internal Medicine and Hypertension, Department of Medical Sciences, University of Turin, Italy (T.A.W.).
FEBS Lett
August 2018
Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.
For decades, researchers in the fertilization field reported various candidate factors involved in sperm-egg interaction through experiments using enzyme inhibitors and/or antibodies. However, almost all of these factors have been shown to be nonessential by gene disruption experiments. Recently, attention has focused on the low reproducibility of papers in many research fields.
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