Expression and chromosomal assignment of PTPH1 gene encoding a cytosolic protein tyrosine phosphatase homologous to cytoskeletal-associated proteins

Signature selection analysis reveals candidate genes associated with production traits in Iranian sheep breeds

BACKGROUND

Sheep were among the first animals to be domesticated. They are raised all over the world and produce a major scale of animal-based protein for human consumption and play an important role in agricultural economy. Iran is one of the important locations for sheep genetic resources in the world. Here, we compared the Illumina Ovine SNP50 BeadChip data of three Iranian local breeds (Moghani, Afshari and Gezel), as a population that does not undergone artificial breeding programs as yet, and five other sheep breeds namely East Friesian white, East Friesian brown, Lacaune, DorsetHorn and Texel to detect genetic mechanisms underlying economical traits and daptation to harsh environments in sheep.

RESULTS

To identify genomic regions that have been targeted by positive selection, we used fixation index (Fst) and nucleotide diversity (Pi) statistics. Further analysis indicated candidate genes involved in different important traits such as; wool production included crimp of wool (PTPN3, NBEA and KRTAP20-2 genes), fiber diameter (PIK3R4 gene), hair follicle development (LHX2 gene), the growth and development of fiber (COL17A1 gene)), adaptation to hot arid environments (CORIN gene), adaptive in deficit water status (CPQ gene), heat stress (PLCB4, FAM107B, NBEA, PIK3C2B and USP43 genes) in sheep.

CONCLUSIONS

We detected several candidate genes related to wool production traits and adaptation to hot arid environments in sheep that can be applicable for inbreeding goals. Our findings not only include the results of previous researches, but also identify a number of novel candidate genes related to studied traits. However, more works will be essential to acknowledge phenotype- genotype relationships of the identified genes in our study.

Genome-Wide Association Study of Staphylococcus aureus Carriage in a Community-Based Sample of Mexican-Americans in Starr County, Texas

Staphylococcus aureus is the number one cause of hospital-acquired infections. Understanding host pathogen interactions is paramount to the development of more effective treatment and prevention strategies. Therefore, whole exome sequence and chip-based genotype data were used to conduct rare variant and genome-wide association analyses in a Mexican-American cohort from Starr County, Texas to identify genes and variants associated with S. aureus nasal carriage. Unlike most studies of S. aureus that are based on hospitalized populations, this study used a representative community sample. Two nasal swabs were collected from participants (n = 858) 11–17 days apart between October 2009 and December 2013, screened for the presence of S. aureus, and then classified as either persistent, intermittent, or non-carriers. The chip-based and exome sequence-based single variant association analyses identified 1 genome-wide significant region (KAT2B) for intermittent and 11 regions suggestively associated with persistent or intermittent S. aureus carriage. We also report top findings from gene-based burden analyses of rare functional variation. Notably, we observed marked differences between signals associated with persistent and intermittent carriage. In single variant analyses of persistent carriage, 7 of 9 genes in suggestively associated regions and all 5 top gene-based findings are associated with cell growth or tight junction integrity or are structural constituents of the cytoskeleton, suggesting that variation in genes associated with persistent carriage impact cellular integrity and morphology.

Regulation of TCR signalling by tyrosine phosphatases: from immune homeostasis to autoimmunity

More than half of the known protein tyrosine phosphatases (PTPs) in the human genome are expressed in T cells, and significant progress has been made in elucidating the biology of these enzymes in T-cell development and function. Here we provide a systematic review of the current understanding of the roles of PTPs in T-cell activation, providing insight into their mechanisms of action and regulation in T-cell receptor signalling, the phenotypes of their genetically modified mice, and their possible involvement in T-cell-mediated autoimmune disease. Our projection is that the interest in PTPs as mediators of T-cell homeostasis will continue to rise with further functional analysis of these proteins, and PTPs will be increasingly considered as targets of immunomodulatory therapies.

Evidence for regulation of the tumor necrosis factor alpha-convertase (TACE) by protein-tyrosine phosphatase PTPH1

Tumor necrosis factor alpha-convertase (TACE) is a metalloprotease-disintegrin involved in the ectodomain shedding of several proteins and is critical for proper murine development. TACE-mediated ectodomain shedding is regulated, and the cytoplasmic domain of TACE contains several potential signaling motifs, suggesting that this domain may play a role in regulating the metalloprotease activity. Here we report that the protein-tyrosine phosphatase PTPH1, which contains both a band 4.1 domain and a single PDZ domain, can interact with the cytoplasmic domain of TACE. The interaction was initially observed in a yeast two-hybrid screen and was confirmed using an in vitro binding assay and co-immunoprecipitations from eukaryotic cell extracts. The interaction is mediated via binding of the PDZ domain of PTPH1 to the COOH terminus of TACE. The latter represents a novel group I PDZ binding sequence characterized by a terminal cysteine residue. In co-expression experiments, significantly lower levels of TACE were observed in the presence of catalytically active forms of PTPH1 compared with catalytically inactive forms of PTPH1. Furthermore, phorbol ester-stimulated shedding of the TACE substrate tumor necrosis factor-alpha was decreased in cells expressing catalytically active PTPH1 compared with inactive PTPH1. Taken together, these results suggest that PTPH1 may be a negative regulator of TACE levels and function, and thus provide the first evidence for the regulation of TACE through a cytoplasmic protein.

Role of butyric acid and its derivatives in the treatment of colorectal cancer and hemoglobinopathies

Butyric acid, a short chain fatty acid (SCFA), is a natural component of the animal metabolism. Physiological concentrations induce multiple and reversible biological effects. They concern regulatory mechanisms of gene expression conducing to promote markers of cell differentiation, apoptosis and cell growth control. The described hyperacetylation of histones and the induction of several immune or non-immune cell-activating mediators are consistent with the pleiotropic stimulatory effect of the agent. Butyric acid is considered as a biological response modifier (BRM) and is an interesting tool for biological studies. The history of butyric acid as a putative medication in human health is spanning since 60 years and is confusing in part because of conflicting data between exciting experimental results and clinical trials. In light of minimal impact of systemic therapy and the short half-life of the saline molecule used, it is evident that continuous infusions of butyrate are required to improve the efficacy of the treatment. Butyric acid has been viewed with skepticism because of less convenient for long-term chronic therapy. New experimental data from several studies conduced within the past decade with butyric derivatives, delivery systems, and long-acting prodrugs, have demonstrated the practical value of the therapeutic concept. To support issues regarding clinical development, it was of interest to evaluate the recent information, showing butyric acid currently considered as therapeutic purposes in the treatment of colorectal cancer and hemoglobinopathies.

Expression of cytoskeletal-associated protein tyrosine phosphatase PTPH1 mRNA in human hepatocellular carcinoma

We investigated the mRNA expression of cytosolic protein tyrosine phosphatase (PTPH1), which has a homologous domain to cytoskeletal-associated proteins, in human hepatocellular carcinomas (HCCs) by using reverse transcriptase-polymerase chain reaction (RT-PCR). PTPH1 mRNA was detected in all HCC cell lines (n = 6), and HCC and adjacent noncancerous tissues (n = 8) examined, indicating that PTPH1 was expressed in HCCs and hepatocytes. There was no remarkable difference in the level expression of PTPH1 mRNA between HCC and adjacent noncancerous tissues. We also performed RT-PCR single-strand conformation polymorphism (SSCP) analysis in HCC cell lines and tissues in the C-terminal region of the catalytic domain of PTPH1. In the cHc4 cell line and a HCC tissue specimen, a shifted band was detected, although it was not found in the non-cancerous tissue of the HCC specimen. Nucleotide sequence analysis showed a common mutation from T to C at the third letter of codon 919 which did not lead to amino acid substitution. These results suggest that another mutation leading to the development of HCC could occur in some region of PTPH1 other than that investigated in this study.