Cloning, Chromosomal Mapping, and Characteristic 5′-UTR Sequence of Murine Cytosolic Sialidase

Kotani, Kiyoshi; Kuroiwa, Asato; Saito, Tamao; Matsuda, Yoichi; Koda, Toshiaki; Kijimoto-Ochiai, Shigeko

doi:10.1006/bbrc.2001.5374

Cited by 31 publications

(21 citation statements)

References 35 publications

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“…In order to examine the gene that controls the sialidase activity at pH 7.0 in the soluble fraction, the activity obtained from the 22 sub-strains was screened for QTL analysis [22], and a candidate was obtained in the region near the marker Mit 8/9 on chromosome 1 (with p=0.001). This result accorded well with our finding by FISH analysis that the Neu2 sialidase gene cloned from the A/J thymus was located on chromosome 1 [9]. We therefore show in Fig.…”

Section: Resultssupporting

confidence: 92%

“…The cloning of this gene has shown that replacement of a few amino acids produces the three Neu1 alleles [7] and that this is the reason for the low activity of the Neu1 a enzyme [8]. Neu2 encodes a soluble cytosolic enzyme [9,10], and Neu3 encodes a plasma membrane enzyme [11,12], while Neu4 encodes a lysozomal and mitochondrial enzyme [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

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Low expression of Neu2 sialidase in the thymus of SM/J mice—existence of neuraminidase positive cells “Neu-medullocyte” in the murine thymus

et al. 2008

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We have already reported that the homogenate of the A/J mouse thymus shows a high sialidase activity at the neutral pH region and that in both soluble and membrane fractions optimal pH was 6.5-7 (Kijimoto-Ochiai et al., Glycoconj. J., 20:375-384, 2004). In the present study, we investigated the level of sialidase activities in the thymus of the SM/J mouse, a mouse strain that we know to have a Neu1 a allele that reveals a low level of sialidase activity in the liver. We found that while in the A/J thymus the soluble sialidase activity at pH 6.5 was high, the SM/J thymus lacked all such activity. A QTL analysis of SMXA recombinant inbred strains showed that soluble sialidase activity correlated well with the D1Mit8/9 marker on chromosome 1. The murine whole DNA-sequence data and the results of our FISH analysis (Kotani et al., Biochem. Biophys. Res. Comm., 286:250-258, 2001) showed that this location is consistent with the position of Neu2 gene. We confirmed that it is hard to detect the Neu2 enzyme of the SM/J mouse thymus by an anti-Neu2 antibody using a Western blot analysis. We also found that Glycoconj J (2008) 25:787-796 while the mRNA expression of Neu2 was quite normal in the SM/J mouse liver, it was very low in the SM/J mouse thymus. We therefore conclude that the lack of soluble sialidase activity in the SM/J mouse thymus is due to the thymus-specific low expression level of the Neu2 gene. We have previously shown that the sialidase positive cell which contains the Mac-1 and immunoglobulin, and which is located sparsely in the corticomedullar region or medullary region of the A/J mouse thymus (Kijimoto-Ochiai et al., Glycoconj. J., 20:375-384, 2004). We showed now in this paper that the detection of this cell in the SM/J mouse thymus at pH 7.0 was difficult. We propose, therefore, to name the cell "Neu-medullocyte".

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Section: Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Low expression of Neu2 sialidase in the thymus of SM/J mice—existence of neuraminidase positive cells “Neu-medullocyte” in the murine thymus

et al. 2008

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“…There are at least four different sialidases in mammalian cells. Sialidase 2 is localized to cellular cytoplasm while Sialidase 1 is localized to lysosome (Igdoura et al, 1998;Kotani et al, 2001;Monti et al, 2002). Cytosolic sialidase is stable and active at pH 7 and can result in the removal of sialic acid from glycoprotein in the culture supernatant (Gramer et al, 1995).…”

Section: Up-regulation Of Degradative Glycosidases During Fed-batch Cmentioning

confidence: 99%

Profiling ofN‐glycosylation gene expression in CHO cell fed‐batch cultures

Wong

Goh

et al. 2010

Biotech & Bioengineering

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One of the goals of recombinant glycoprotein production is to achieve consistent glycosylation. Although many studies have examined the changes in the glycosylation quality of recombinant protein with culture, very little has been done to examine the underlying changes in glycosylation gene expression as a culture progresses. In this study, the expression of 24 genes involved in N-glycosylation were examined using quantitative RT PCR to gain a better understanding of recombinant glycoprotein glycosylation during production processes. Profiling of the N-glycosylation genes as well as concurrent analysis of glycoprotein quality was performed across the exponential, stationary and death phases of a fed-batch culture of a CHO cell line producing recombinant human interferon-gamma (IFN-gamma). Of the 24 N-glycosylation genes examined, 21 showed significant up- or down-regulation of gene expression as the fed-batch culture progressed from exponential, stationary and death phase. As the fed-batch culture progressed, there was also an increase in less sialylated IFN-gamma glycoforms, leading to a 30% decrease in the molar ratio of sialic acid to recombinant IFN-gamma. This correlated with decreased expression of genes involved with CMP sialic acid synthesis coupled with increased expression of sialidases. Compared to batch culture, a low glutamine fed-batch strategy appears to need a 0.5 mM glutamine threshold to maintain similar N-glycosylation genes expression levels and to achieve comparable glycoprotein quality. This study demonstrates the use of quantitative real time PCR method to identify possible "bottlenecks" or "compromised" pathways in N-glycosylation and subsequently allow for the development of strategies to improve glycosylation quality.

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“…Recently, we demonstrated that its overexpression induces a marked decrement of proliferation and spontaneous differentiation of myoblast C2C12 cells [16]. Although the sialidase Neu2 is expressed in other tissues such as liver [17], thymus [18] and brain [19], its enzymatic activity is often hardly detectable, thus making its study difficult.…”

Section: Discussionmentioning

confidence: 99%

“…Despite its relative abundance in skeletal muscle, cytosolic sialidase was found also in other tissues, such as liver [17], thymus [18] and, although at low levels, brain [19].…”

Section: Introductionmentioning

confidence: 99%

Cytosolic sialidase Neu2 upregulation during PC12 cells differentiation

FANZANI

2004

FEBS Letters

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The cytosolic sialidase Neu2 is known to be involved in myoblast differentiation. Here, we observed a Neu2 transcriptional induction during nerve growth factor, fibroblast growth factor 2 and epidermal growth factor treatments of PC12 cells, a favored model to study neuronal differentiation. The expression analysis of Neu2 deleted promoter revealed a remarkable increase of luciferase activity in treated PC12 cells, suggesting that in this cell line the Neu2 transcriptional levels are highly regulated.The enzymatic activity of cytosolic sialidase Neu2 was found to increase transiently only during differentiation, whereas was undetectable in untreated PC12 cells. These data suggest a possible involvement of cytosolic sialidase Neu2 in differentiation of PC12 cells.

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Cloning, Chromosomal Mapping, and Characteristic 5′-UTR Sequence of Murine Cytosolic Sialidase

Cited by 31 publications

References 35 publications

Low expression of Neu2 sialidase in the thymus of SM/J mice—existence of neuraminidase positive cells “Neu-medullocyte” in the murine thymus

Low expression of Neu2 sialidase in the thymus of SM/J mice—existence of neuraminidase positive cells “Neu-medullocyte” in the murine thymus

Profiling ofN‐glycosylation gene expression in CHO cell fed‐batch cultures

Cytosolic sialidase Neu2 upregulation during PC12 cells differentiation

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