Regulation of protein phosphatase activity by regucalcin localization in rat liver nuclei

Omura, Masami; Yamaguchi, Masayoshi

doi:10.1002/(sici)1097-4644(19991201)75:3<437::aid-jcb9>3.3.co;2-n

Cited by 5 publications

(10 citation statements)

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“…An earlier study reported that regucalcin is secreted, at significant concentrations, into buffalo seminal vesicular fluid (Harikrishna et al, ), yet we did not detect this protein in the seminal plasma separated from ejaculated semen. One possible reason for this may be its transfer from seminal plasma to spermatozoa, which is consistent with the reported translocation of exogenous regucalcin to the nucleus of osteoblasts (Otomo and Yamaguchi, ) and liver cells (Omura and Yamaguchi, ), where it alters gene expression and modulates enzyme activity. Another possibility is that the regucalcin was diluted to undetectable levels— although we failed to detect a band even after probing higher total volumes of seminal plasma.…”

Section: Discussionsupporting

confidence: 80%

Regucalcin is widely distributed in the male reproductive tract and exerts a suppressive effect on in vitro sperm capacitation in the water buffalo (Bubalus bubalis)

Pillai

Shende

Parmar

et al. 2017

Molecular Reproduction Devel

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Regucalcin is a multi-functional, calcium-binding protein with roles in calcium homeostasis, apoptosis, cell proliferation, and free radical neutralization. Regucalcin is broadly expressed in the male reproductive organs of rat and bovine; here, we report its expression in the reproductive tract of male buffalo-especially in testis, epididymis, seminal vesicle, prostate, and bulbourethral gland of buffalo-as analyzed by real-time PCR, Western blot, and immunolocalization. Regucalcin degradation in seminal plasma, despite its high abundance in vesicular fluid, was demonstrated using recombinant regucalcin co-incubated with buffalo seminal plasma. This depletion of regucalcin appears to be related to its suppressive effect on in vitro sperm capacitation, observed using the chlortetracycline assay after treating buffalo spermatozoa with recombinant protein. Indeed, addition of recombinant regucalcin to capacitating media significantly reduced (P < 0.05) the percentage of capacitated spermatozoa to 6.1 ± 0.6 from 36.4 ± 1.8 in the untreated group. Taken together, the wide distribution of regucalcin in male buffaloes, versus its degradation in the seminal plasma and suppressive effects on in vitro capacitation of spermatozoa, indicate its possible anti-capacitation role in the reproductive tract. Mol. Reprod. Dev. 84: 212-221, 2017. © 2016 Wiley Periodicals, Inc.

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Section: Discussionsupporting

confidence: 80%

Regucalcin is widely distributed in the male reproductive tract and exerts a suppressive effect on in vitro sperm capacitation in the water buffalo (Bubalus bubalis)

Pillai

Shende

Parmar

et al. 2017

Molecular Reproduction Devel

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“…Regucalcin plays a role in maintaining intracellular Ca 2+ homeostasis, the inhibitory regulation of various Ca 2+dependent protein kinases and tyrosine kinases, protein phosphatases, nitric oxide synthase, and the control of the enhancement of protein synthesis, nuclear deoxyribonucleic acid (DNA) and RNA synthesis in proliferative cells (6)(7)(8)(18)(19)(20)(21)(22)(23)(24)(25). Recent study has demonstrated that regucalcin has suppressive effects on cell proliferation and apoptosis, which are mediated through many signaling factors, in cloned rat hepatoma H4-II-E cells and normal rat kidney proximal tubular epithelial NRK52E cells overexpressing regucalcin (26)(27)(28).…”

Section: Introductionmentioning

confidence: 99%

Regulatory effect of exogenous regucalcin on cell function in osteoblastic MC3T3-E1 cells: Involvement of intracellular signaling factor

Otomo

Yamaguchi²

2006

Int J Mol Med

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Bone loss is induced in regucalcin transgenic rats. The role of exogenous regucalcin in the regulation of osteoblastic cell function was investigated. Osteoblastic MC3T3-E1 cells with subconfluent monolayers were cultured for 24-72 h in medium containing regucalcin (10-10 or 10-9 M) without fetal bovine serum. The presence of regucalcin did not have a significant effect on cell number. Culture with regucalcin (10-9 M) for 24 h caused a significant decrease in protein and DNA contents in osteoblastic cells. The effect of regucalcin in decreasing cellular protein content was significantly inhibited in the presence of various kinase inhibitors including staurosporine (10-7 M), dibucaine (10-6 M), PD98059 (10-8 M), or wortmannin (10-8 M). Meanwhile, culture with regucalcin caused a significant decrease in cellular DNA content in the presence of various kinase inhibitors. The presence of regucalcin did not have a significant effect on protein and DNA contents in the cells cultured with cycloheximide (10-7 M), an inhibitor of protein synthesis, or 5,6-dichloro-1-ß-D-ribofuranosylbenzimidazole (10-6 M), an inhibitor of transcription activity; which each inhibitor caused a significant decrease in those contents. The effect of regucalcin in decreasing cellular protein content was seen in the presence of insulin-like growth factor-I (IGF-I; 10-9 or 10-8 M). Such an effect was not observed in cellular DNA content. The results of reverse transcription-polymerase chain reaction analysis with specific primers showed that the expression of Runx 2 (Cbfa 1) and alkaline phosphatase mRNAs in osteoblastic cells was significantly suppressed in the presence of regucalcin (10-10 or 10-9 M). Glyceraldhyde-3phosphate dehydrogenase mRNA level was not significantly changed with culture of regucalcin (10-10 or 10-9 M). This study supports the view that exogenous regucalcin regulates the function of osteoblastic cells, and that the effect of protein is mediated through signaling factors.

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“…The presence of RGN mRNA suggests the possibility of RGN protein synthesis either in germ cells or spermatozoa or in both. Another possibility is by translocation of RGN into spermatozoa from the external source as it has been detected in the secretions of male reproductive tract (Harikrishna, Shende, Reena, et al., ; Laurentino et al., ), and there are reports of translocation of exogenous RGN to the nucleus of osteoblasts (Otomo & Yamaguchi, ) and liver cells (Omura & Yamaguchi, ). Further studies are needed to investigate whether the RGN associated with spermatozoa is of endogenous origin only or both endogenous and exogenous origin.…”

Section: Discussionmentioning

confidence: 99%

Detection and localization of regucalcin in spermatozoa of water buffalo (Bubalus bubalis): A calcium‐regulating multifunctional protein

Pillai

Shende

Parmar

et al. 2017

Reprod Domestic Animals

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Regucalcin (RGN) is a calcium-regulating, anti-apoptotic, antioxidative and antiproliferative multifunctional protein predominantly seen in liver and kidney. All these functions are very crucial during spermatogenesis and sperm maturation process until fertilization of the ovum. Although many studies have reported the wide distribution of regucalcin in the male reproductive tract of the rat, human and bovine, its presence in spermatozoa is yet to be demonstrated wherein calcium has a pivotal role in the transport, capacitation, acrosomal reaction and further fusion with ova. Here, we detected the expression of regucalcin mRNA and protein in buffalo spermatozoa using real-time PCR and Western blot, respectively. The study detected two new regucalcin isoforms of 44 kDa and 48 kDa size along with the reported 34-kDa, 28-kDa and 24-kDa isoforms, wherein the 34-kDa isoform was found to be membrane associated in spermatozoa. Further, immunocytochemistry study localized the regucalcin protein in the acrosomal region of the caudal and ejaculated buffalo spermatozoa while it was detected in both cytoplasm and acrosomal region of testicular spermatozoa. This discovery of RGN in spermatozoa and localization in the acrosomal region will help to focus researchers to see its role in calcium-related functions like capacitation, acrosomal reaction and membrane fusion. Overall, regucalcin may be a new fertility marker in buffalo and can be utilized for infertility treatments.

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Regulation of protein phosphatase activity by regucalcin localization in rat liver nuclei

Cited by 5 publications

References 0 publications

Regucalcin is widely distributed in the male reproductive tract and exerts a suppressive effect on in vitro sperm capacitation in the water buffalo (Bubalus bubalis)

Regucalcin is widely distributed in the male reproductive tract and exerts a suppressive effect on in vitro sperm capacitation in the water buffalo (Bubalus bubalis)

Regulatory effect of exogenous regucalcin on cell function in osteoblastic MC3T3-E1 cells: Involvement of intracellular signaling factor

Detection and localization of regucalcin in spermatozoa of water buffalo (Bubalus bubalis): A calcium‐regulating multifunctional protein

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