Identification of a non-purple tartrate-resistant acid phosphatase: an evolutionary link to Ser/Thr protein phosphatases?

BACKGROUND Tartrate-resistant acid phosphatases (TRAcPs), also known as purple acid phosphatases (PAPs), are a family of binuclear metallohydrolases that have been identified in plants, animals and fungi. The human enzyme is a major histochemical marker for the diagnosis of bone-related diseases. TRAcPs can occur as a small form possessing only the ~35 kDa catalytic domain, or a larger ~55 kDa form possessing both a catalytic domain and an additional N-terminal domain of unknown function. Due to its role in bone resorption the 35 kDa TRAcP has become a promising target for the development of anti-osteoporotic chemotherapeutics. FINDINGS A new human gene product encoding a metallohydrolase distantly related to the ~55 kDa plant TRAcP was identified and characterised. The gene product is found in a number of animal species, and is present in all tissues sampled by the RIKEN mouse transcriptome project. Construction of a homology model illustrated that six of the seven metal-coordinating ligands in the active site are identical to that observed in the TRAcP family. However, the tyrosine ligand associated with the charge transfer transition and purple color of TRAcPs is replaced by a histidine. CONCLUSION The gene product identified here may represent an evolutionary link between TRAcPs and Ser/Thr protein phosphatases. Its biological function is currently unknown but is unlikely to be associated with bone metabolism.This work was funded by the Royal Society of Tropical Medicine and Hygiene through a Dennis Burkitt Fellowship to JJM. ARD is supported by the Economic and Social Research Council. JJM is supported by a Wellcome Trust Research Training Fellowship (GR074833MA)

Monomeric Tartrate Resistant Acid Phosphatase Induces Insulin Sensitive Obesity

Obesity is associated with macrophage infiltration of adipose tissue, which may link adipose inflammation to insulin resistance. However, the impact of inflammatory cells in the pathophysiology of obesity remains unclear

Mammal responses to global changes in human activity vary by trophic group and landscape

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.Peer reviewe

Isolation and characterization of the genes encoding mouse and human type-5 acid phosphatase

The gene (mT5AP) encoding murine type-5 acid phosphatase has been isolated and completely sequenced while the gene (hT5AP) encoding human T5AP has been partly sequenced. The murine gene spans 4 kb and contains five exons. Exon 1 is completely non-coding and exon 2 starts with the initiation codon in both mT5AP and hT5AP. The positions of the intron/exon boundaries are completely conserved between mT5AP and hT5AP, but are distinct from the gene encoding the related porcine protein, uteroferrin (Utf). There is strong homology at both the nucleotide (nt) and amino acid (aa) levels between the inferred mouse cDNA and the sequences of rat T5AP and hT5AP, and pig Utf. The mT5AP and hT5AP genes were found to have multiple transcription start points (tsp) by primer extension analysis, consistent with the absence of a consensus TATA box. The sequences for the 5'-flanking regions of mT5AP and hT5AP were determined to -1.6 and -1.0 kb, respectively, relative to the tsp. A 2-kb segment of the mT5AP 5' flanking region linked to a luciferase-encoding reporter gene (Luc) was sufficient to direct tissue-specific transcription in the mouse macrophage cell line, RAW264. Significant sequence similarity between the mT5AP and hT5AP promoters is restricted to the most proximal 200 bp, which also resembles the porcine Utf gene, and a 300-bp segment 700 bp upstream. A progesteroneresponse element is present only in the mouse promoter and the estrogen- and iron-response elements described previously in the pig gene are absent from both the mouse and human genes. These differences may result in distinctive regulation of T5AP and Utf expression

Cloning and characterization of the murine genes for bHlH-ZIP transcription factors TFEC and TFEB reveal a common gene organization for all MiT subfamily members

The microphthalmia-TFE (MiT) subfamily of basic helix-loop-helix leucine zipper (bHLH-ZIP) transcription factors, including TFE3, TFEB, TFEC, and Mitf, has been implicated in the regulation of tissue-specific gene expression in several cell lineages. In this report, we investigate the genomic organization and structural relatedness of MiT transcription factors. We characterized the gene for mTFEC, which covers a region of more than 50 kb and is composed of seven exons. Further, we cloned a cDNA for the murine TFEB homologue and characterized its genomic structure. The eight coding exons of mTFEB are distributed over a 6-kb region. A multiple alignment of amino acid sequences of known MiT subfamily members indicates undescribed, conserved N- terminal regions and common putative phosphorylation sites for TFE3, TFEB, and Mitf. Also, intron-exon borders for characterized MiT genes appear completely conserved. A new family member and closely related putative transcription factor in Caenorhabditis elegans was identified by database searches that show a similar genomic organization within the bHLH-ZIp region and the acidic domain. Evolutionary aspects and implications for structure- function relationships are discussed

Transgenic mice that overexpress the tartrate-resistant acid phosphatase gene exhibit in an increased rate of bone turnover

Tartrate-resistant acid phosphatase (TRAP) is a secreted product of osteoclasts and a lysosomal hydrolase of some tissue macrophages. To determine whether TRAP expression is rate-limiting in bone resorption, we overexpressed TRAP in transgenic mice by introducing additional copies of the TRAP gene that contained the SV40 enhancer. In multiple independent mouse lines, the transgene gave a copy number-dependent increase in TRAP mRNA levels and TRAP activity in osteoclasts, macrophages, serum, and other sites of normal low-level expression (notably, liver parenchymal cells, kidney mesangial cells, and pancreatic secretory acinar cells). Transgenic mice had decreased trabecular bone consistent with mild osteoporosis. Measurements of the bone formation rate suggest that the animals compensate for the increased resorption by increasing bone synthesis, which partly ameliorates the phenotype. These mice provide evidence that inclusion of an irrelevant enhancer does not necessarily override a tissue-specific promoter