Proteome profiling of enriched membrane-associated proteins unraveled a novel sophorose and cello-oligosaccharide transporter in Trichoderma reesei.

BACKGROUND: Trichoderma reesei is an organism extensively used in the bioethanol industry, owing to its capability to produce enzymes capable of breaking down holocellulose into simple sugars. The uptake of carbohydrates generated from cellulose breakdown is crucial to induce the signaling cascade that triggers cellulase production. However, the sugar transporters involved in this process in T. reesei remain poorly identified and characterized. RESULTS: To address this gap, this study used temporal membrane proteomics analysis to identify five known and nine putative sugar transporters that may be involved in cellulose degradation by T. reesei. Docking analysis pointed out potential ligands for the putative sugar transporter Tr44175. Further functional validation of this transporter was carried out in Saccharomyces cerevisiae. The results showed that Tr44175 transports a variety of sugar molecules, including cellobiose, cellotriose, cellotetraose, and sophorose. CONCLUSION: This study has unveiled a transporter Tr44175 capable of transporting cellobiose, cellotriose, cellotetraose, and sophorose. Our study represents the first inventory of T. reesei sugar transportome once exposed to cellulose, offering promising potential targets for strain engineering in the context of bioethanol production.

Targeted Mass Spectrometry of S100 Proteins.

The S100 protein family has attracted great interest in the field of biomarker research, and a growing number of studies reveal dysregulation of many of the 21 S100 protein isoforms in various human diseases. In cancer, S100 protein expression has been associated with tumor growth, progression, and response to treatment. Some S100 proteins are also considered candidate therapeutic targets. From an analytical perspective, multiplexed analysis of the family-wide S100 protein expression is challenging due to their relatively small size and high-sequence identity. Here we describe a mass spectrometry method using selected reaction monitoring which enables the targeted, multiplexed detection and quantitation of the entire S100 protein family in cell lines and tissue samples.

Proteomic profile of sex-sorted bull sperm evaluated by SWATH-MS analysis.

The identification of distinct proteins present on the membrane of spermatozoa with X and Y chromosomes allows the development of immuno-sexing techniques. The aim of this study, therefore, was to use mass spectrometry to analyze the protein profile of sperm previously categorized using flow cytometry into X or Y-bearing semen pools. Sex-sorted sperm samples (n = 6 X and n = 6 Y) were used. Proteins were extracted and analyzed by mass spectrometry using data independent acquisition (DIA). The data were searched against taxonomy Bos taurus in the Swiss Prot database. In total, 459 protein groups were identified. Of these, eight proteins were in differential abundances between the X- and Y-bearing sperm population. Among the major proteinsdetected, EF-hand domain-containing protein 1, a protein involved in embryonic development, is more abundant in Y-bearing spermatozoa. In addition, proteins FUN14, domain-containing protein 2, NADH dehydrogenase [ubiquinone] iron-sulfur protein 7 mitochondrial, cytochrome C oxidase subunit 2, acetyl -CoA carboxylase type beta were more abundant in X-bearing sperm. In conclusion, there were differences in abundance of proteins between X- and Y-bearing bull spermatozoa. This fact, may contribute to future studies related to sperm physiology and possibility development of immuno-sexing techniques.