Biology subjects

Hukelmann, J. L.

Publications and source records attributed to Hukelmann, J. L..

2 recordsLinked to original sources

bioRxiv2018

Antigen receptor control of methionine metabolism in T cells

Immune activated T lymphocytes modulate the activity of key metabolic pathways to support the transcriptional reprograming and reshaping of cell proteomes that permits effector T cell differentiation. The present study uses high resolution mass spectrometry and metabolic labelling to explore how T cells control the methionine cycle to produce methyl donors for protein and nucleotide methylations. We show that antigen receptor engagement controls flux through the methionine cycle and also controls RNA and histone methylations. We establish that the main rate limiting step for the methionine cycle is control of methionine transporter expression by antigen receptors. Only T cells that respond to antigen to upregulate and sustain methionine transport are supplied with the methyl donors that permit the dynamic nucleotide methylations and epigenetic reprogramming that drives T cell differentiation.

immunology↗

bioRxiv2018

Optimising multi-batch TMT analysis to mitigate inflation of missing values, false positives and diminished inter batch accuracy

Multiplexing strategies for large-scale proteomic analyses have become increasingly prevalent, TMT in particular. Here we used a large iPSC proteomic experiment with twenty-four 10-plex TMT batches to evaluate the effect of integrating multiple TMT batches within a single analysis. We reveal a significant inflation rate of missing protein and peptide values and show that precision decreases as multiple batches are integrated. Additionally, we explore the effect of false positives using Y chromosome specific peptides as an internal control to quantify the effect of co-isolation interference, as well as primary and secondary reporter ion interference. Based on the results we suggest solutions to mitigate these effects. We show using a reference line can increase precision by normalising the quantification across batches and we propose experimental designs that minimise the effect of cross population reporter ion interference.

biochemistry↗