Trypanosoma brucei is a unicellular parasite transmitted between African mammals by tsetse flies. T. brucei multiplies freely in the bloodstream of many different mammals, and survives by antigenic variation of the main component of its surface coat, variant surface glycoprotein (VSG). Trypanosomes take up transferrin through a heterodimeric transferrin receptor, the genes for which are expressed in telomeric expression sites along with the VSG gene. There are up to 20 of these expression sites per trypanosome nucleus, but usually only one is active at a time. Different expression sites encode transferrin receptors that are similar but not identical. Here we show that these small differences between transferrin receptors can have profound effects on the binding affinity for transferrins from different mammals, and on the ability of trypanosomes to grow in the sera of these mammals. Our results suggest that the ability to switch between different transferrin-receptor genes allows T. brucei to cope with the large sequence diversity in the transferrins of its hosts.
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http://dx.doi.org/10.1038/35166 | DOI Listing |
PLoS One
January 2025
Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.
Adult neurogenesis has most often been studied in the hippocampus and subventricular zone-olfactory bulb, where newborn neurons contribute to a variety of behaviors. A handful of studies have also investigated adult neurogenesis in other brain regions, but relatively little is known about the properties of neurons added to non-canonical areas. One such region is the striatum.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, People's Republic of China.
Carrier-free nanomedicines exhibited significant potential in elevating drug efficacy and safety for tumor management, yet their self assembly typically relied on chemical modifications of drugs or the incorporation of surfactants, thereby compromising the drug's inherent pharmacological activity. To address this challenge, we proposed a triethylamine (TEA)-mediated protonation-deprotonation strategy that enabled the adjustable-proportion self assembly of dual drugs without chemical modification, achieving nearly 100% drug loading capacity. Molecular dynamic simulations, supported by experiment evidence, elucidated the underlying self-assembly mechanism.
View Article and Find Full Text PDFCancer Res Commun
January 2025
University of Minnesota, Minnesota, MN, United States.
Neuroendocrine neoplasms (NENs) encompass a diverse set of malignancies with limited precision therapy options. Recently, therapies targeting DLL3 have shown clinical efficacy in aggressive NENs, including small cell lung cancers and neuroendocrine prostate cancers. Given the continued development and expansion of DLL3-targeted therapies, we sought to characterize the expression of DLL3 and identify its clinical and molecular correlates across diverse neuroendocrine and non-neuroendocrine cancers.
View Article and Find Full Text PDFGenes Genomics
January 2025
Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
Background: Cervical cancer is the fourth most common cancer worldwide in females. This occurs primarily due to the infection of high-risk Human Papilloma Virus (HPV), although in advanced stages it requires support from host cellular factors. BRN3A is one such host cellular factors, whose expression remains high in cervical cancers and upregulates tumorigenic HPV gene expression.
View Article and Find Full Text PDFmBio
January 2025
Department of Microbiology, UMass Chan Medical School, Worcester, Massachusetts, USA.
Unlabelled: (Mtb) exhibits an impressive ability to adapt to rapidly changing environments, despite its genome's apparent stability. Recently, phase variation through indel formation in homopolymeric tracts (HT) has emerged as a potentially important mechanism promoting adaptation in Mtb. This study examines the impact of common phase variants associated with the ESX-1 type VII secretion system, focusing on a highly variable HT upstream of the ESX-1 regulatory factor, .
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