• BMB Reports
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• v.45 no.12
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• pp.693-699
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• 2012

Together with protein tyrosine kinases (PTKs), protein tyrosine phosphatases (PTPs) serve as hallmarks in cellular signal transduction by controlling the reversible phosphorylation of their substrates. The human genome is estimated to encode more than 100 PTPs, which can be divided into eleven sub-groups according to their structural and functional characteristics. All the crystal structures of catalytic domains of sub-groups have been elucidated, enabling us to understand their precise catalytic mechanism and to compare their structures across all sub-groups. In this review, I describe the structure and mechanism of catalytic domains of PTPs in the structural context.

• BMB Reports
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• v.43 no.9
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• pp.579-583
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• 2010

The adipocyte-derived hormone leptin regulates appetite and bone mass. Recent research demonstrates that reciprocally, osteoblasts have a role in controlling energy metabolism. Several genes expressed in osteoblasts are involved in this process, and one of them is the Esp gene. The remaining genes regulate Esp gene expression. OST-PTP, the protein name of Esp, regulates the carboxylation of osteocalcin secreted from osteoblasts, thus affecting insulin sensitivity and insulin secretion. This review provides evidence for a novel interpretation of the connection between bone and energy metabolism and expands our understanding of the novel physiology of bone beyond its classical functions.