PubMed · 7044227
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Y Itokawa, M Kimura, K Nishino. 1982. Thiamin-binding proteins.. https://doi.org/10.1111/j.1749-6632.1982.tb31207.x
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Uteroferrin is an iron-binding glycoprotein, which is abundantly synthesized in porcine uterine glandular endometrium and believed to be involved in maternal/fetal iron transport. In the present study, uteroferrin has been cloned and functionally expressed using baculovirus-infected insect host cells Spodoptera frugiperda. The work also addresses the possible role of proteolytic cleavage to facilitate the release of uteroferrin-bound iron. The enzyme secreted in culture medium exhibits a molecular mass and catalytic properties similar to native porcine uteroferrin. The specific activity was estimated at 233 U/mg using p-nitrophenyl phosphate as substrate. Partial cleavage of the enzyme with trypsin resulted in a 1.7-fold enhancement in specific activity and a two-subunit polypeptide as observed in preparations of most mammalian purple acid phosphatases. Digestion with the aspartic protease pepsin resulted in a 2.5-fold enzyme inactivation correlated with the appearance of low molecular weight polypeptide fragments and the release of enzyme-bound iron.
We report a novel spontaneous mutation named nax in mice, which exhibit delayed hair appearance and ataxia in a homozygote state. Histological analyses of nax brain revealed an overall impairment of the cerebellar cortex. The classical cortical cytoarchitecture was disrupted, the inner granule cell layer was not obvious, the Purkinje cells were not aligned as a Purkinje cell layer, and Bergmann glias did not span the molecular layer. Furthermore, histological analyses of skin showed that the hair follicles were also abnormal. We mapped the nax locus between marker D2Mit158 and D2Mit100 within a region of 800 kb in the middle of chromosome 2 and identified a missense mutation (Gly244Glu) in Acp2, a lysosomal monoesterase. The Glu244 mutation does not affect the stability of the Acp2 transcript, however it renders the enzyme inactive. Ultrastructural analysis of nax cerebellum showed lysosomal storage bodies in nucleated cells, suggesting progressive degeneration as the underlying mechanism. Identification of Acp2 as the gene mutated in nax mice provides a valuable model system for studying the role of Acp2 in cerebellum and skin homeostasis.
We investigated time-course changes in the expression of receptor activator of nuclear factor-kappaB (RANK), its ligand (RANKL), osteoprotegerin (OPG), bone-type alkaline phosphatase (BAP), and tartrate-resistant acid phosphatase (TRAP) in ovariectomized (OVX) rats. Samples of sera and coccyges were used for analysis of the enzyme activities and expression levels of proteins and mRNAs, and an immunohistochemical analysis was also performed. Serum BAP activity increased to 158.6% of the pre-operation value at 1 week after OVX, and then decreased to 38.7% at 8 weeks after OVX. On the other hand, the serum TRAP activity increased to 130.9% of the pre-operation level at 1 week after OVX, and was maintained at a high level, compared with the pre-operation level. The patterns of BAP and TRAP activity in the coccyges specimens were similar to those seen in the sera. The expression profiles of TRAP, RANK, and RANKL proteins in the coccyx specimens were similar to the pattern of serum TRAP activity, while the profiles of the BAP and OPG proteins were similar to the pattern of serum BAP activity in OVX rats. The changes in the mRNA expression levels of the osteogenic proteins were similar to those for protein expression. These biochemical changes in OVX rats were confirmed by immunohistochemical studies. Our results suggest that not only osteoclastogenesis accelerated but also osteoblastogenesis transiently increased during the early phase of osteoporosis.