Disease relevance of Neu2

• The levels of lysosomal and cytosolic sialidase activities in liver and hepatomas were then studied in the pellet and supernatant fractions, respectively, obtained by centrifuging the postnuclear supernatant at 105,000g for 1 hr [1].

High impact information on Neu2

• When subjected to sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis, the purified cytosolic sialidase moved as a single protein band with Mr = 43,000, a value similar to that obtained by sucrose density gradient centrifugation [2].
• The results of a backcross analysis involving the KGH and ACP strains revealed that NEU-1 and NEU-2 phenotypes are independently controlled, each by a single autosomal locus with additively acting alleles [3].
• NEU-2 and the gene controlling its phenotype were not detected by the fluorometric technique [3].
• An investigation of the activity of recombinant rat skeletal muscle cytosolic sialidase [4].
• Rat cytosolic sialidase is expressed at elevated levels in skeletal muscle and is believed to play a role in the myogenic differentiation of muscle cells [4].

Biological context of Neu2

• Here we observed a significant upregulation of Neu2 expression during differentiation of murine C2C12 myoblasts [5].
• Neu2 overexpressing clones were characterized by a marked decrement of cell proliferation and by the capacity to undergo spontaneous myoblast differentiation also when maintained under standard growth conditions [5].
• Finally, an investigation of the enzymatic hydrolysis of a synthetic substrate, 4-methylumbelliferyl N-acetyl-alpha-D-neuraminide, by 1H NMR spectroscopy revealed that the reaction catalysed by rat skeletal muscle cytosolic sialidase proceeds with overall retention of anomeric configuration [4].
• Rat-liver lysosomal sialidase. Solubilization, substrate specificity and comparison with the cytosolic sialidase [6].
• We have previously observed that the cytosolic sialidase gene is highly expressed in rat skeletal muscle and that it contains an enhancer/promoter region which is transcriptionally active in rat L6 myogenic cells [7].

Anatomical context of Neu2

• We have previously shown that chronic ethanol feeding stimulates liver cytosolic sialidase (CS) and plasma membrane sialidase (PMS), whereas it decreases lysosomal membrane sialidase (LMS) activities with concomitant alterations in their relative synthetic rate in rat [8].
• 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 [9].
• We have previously cloned a cDNA of a rat cytosolic sialidase which is strongly expressed in skeletal muscle [10].
• Myotube formation can, in fact, be blocked by the addition of an antisense oligodeoxyribonucleotide complementary to the first 8 codons of the cytosolic sialidase [7].
• Immunohistochemical localization of cytosolic sialidase in photoreceptor cells [11].

Associations of Neu2 with chemical compounds

• Thus, the upregulation of CS and PMS, but not LMS which is down regulated by chronic ethanol, may account for the appearance of asialoconjugates in alcoholics [8].
• 1% (p<0.05) and 42.6% (p<0.05) increased activities of sialidases, respectively, in the cytosol and plasma membrane fractions; and (4) a 22.2%-64.3% (p<0.001) increased incorporation of labeled leucine into brain cytosolic sialidase [12].
• A heavy metal ion such as Cu2+ (1 mM) and thiol-modifying 4-hydroxymercuribenzoate (50 microM) caused complete inhibition of the activities of cytosolic sialidase and membrane sialidase I, while no decrease in the activities of intralysosomal sialidase and membrane sialidase II was observed [13].

Other interactions of Neu2

• 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 [9].
• Ethanol feeding at 36% dietary calories caused an increase in the ganglioside sialidase activity of the plasma membrane sialidase (PMS) by 232% (P < .01) and that of cytosolic sialidase (CS) by 184% (P < .05), but decreased the lysosomal membrane sialidase (LMS) by 54% (P < .01) when compared with the control animals [14].

Analytical, diagnostic and therapeutic context of Neu2

• Western blot analyses of CS, PMS, and LMS in the liver subfractions showed that changes in protein levels of CS, LMS, and PMS were consistent with the corresponding changes in the respective mRNA levels [8].

References