Biology subjects

Martin-Gonzalez, J.

Publications and source records attributed to Martin-Gonzalez, J..

4 recordsLinked to original sources

bioRxiv2026

Pulsed-SILAC in single mouse embryos reveals early embryonic protein synthesis dynamics and phosphosite regulation

Early embryogenesis relies extensively on maternally deposited products until zygotic genome activation, yet the dynamics for the synthesis of new proteins in mammalian embryos remains poorly characterized. To address this, we applied pulsed stable isotope labelling by amino acids in cell culture (pSILAC) combined with narrow-window data-independent acquisition mass spectrometry to single mouse oocytes and embryos to resolve de novo protein synthesis during early embryogenesis. This revealed that the maternal proteome is not a static reservoir, with components of the subcortical maternal complex and amino acid transporters SLC7A1/2 being actively synthesized during the earliest developmental stages. Furthermore, phosphoproteomic analysis identified hundreds of previously unreported phosphosites and extensive regulation during the oocyte-to-embryo transition. Notably, phosphorylation of the PRC2-interacting KLP motif of EZHIP emerged as a potential regulatory mechanism, with modification of this region reducing EZHIP-PRC2 interaction and coinciding with H3K27me3 remodelling. Together, single embryo pSILAC revealed a maternal proteome that is continuously synthesized, recycled, and post-translationally regulated during early embryogenesis.

cell biology↗

bioRxiv2023

Sex-Specific DNA-Replication In The Early Mammalian Embryo

The timing of mammalian DNA replication is crucial for minimizing errors and is influenced locally by genome usage and chromatin states. However, our understanding of replication timing in the unique environment that exists in newly formed mammalian embryos is limited. Here, we performed genome-wide investigations of replication timing in mouse zygotes and 2-cell embryos. We discovered that zygotes lack a conventional replication timing, but a program emerged in 2-cell embryos. Notably, this program differs from embryonic stem cells and shows asynchrony between the parental genomes. We observed late replication of maternal pericentromeric regions and DNA associated with the nuclear lamina in each parental genome, whereas unexpected early replication occurred in regions with histone marks deposited by Polycomb Repressive Complexes on the maternal chromatin. This atypical and asynchronous replication of the two parental genomes may advance our understanding of replication stress in early human embryos and trigger strategies to reduce errors and aneuploidies.

genomics↗

bioRxiv2023

One-Tip enables comprehensive proteome coverage in minimal cells and single zygotes

We present One-Tip, a lossless proteomics methodology that seamlessly combines swift, one-pot sample preparation with narrow-window data-independent acquisition mass spectrometric analysis. With simplest sample processing, One-Tip reproducibly identifies > 9,000 proteins from [~]1000 cells and [~] 6,000 proteins in a single mouse zygote with a throughput of 40 samples-per-day. This easy-to-use method expands capabilities of proteomics research by enabling greater depth, scalability and throughput covering low to high input samples.

biochemistry↗

bioRxiv2020

The SPIRE1 actin nucleator coordinates actin/myosin functions in the regulation of mitochondrial motility

Subcellular localisation of mitochondria provides a spatial and temporal organisation for cellular energy demands. Long-range mitochondrial transport is mediated by microtubule tracks and associated dynein and kinesin motor proteins. The actin cytoskeleton has a more versatile role and provides transport, tethering, and anchoring functions. SPIRE actin nucleators organise actin filament networks at vesicle membranes, which serve as tracks for myosin 5 motor protein-driven transport processes. Following alternative splicing, SPIRE1 is targeted to mitochondria. In analogy to vesicular SPIRE functions, we have analysed whether SPIRE1 regulates mitochondrial motility. By tracking mitochondria of living fibroblast cells from SPIRE1 mutant mice and splice-variant specific mitochondrial SPIRE1 knockout mice, we determined that the loss of SPIRE1 function increased mitochondrial motility. The SPIRE1 mutant phenotype was reversed by transient overexpression of mitochondrial SPIRE1, which almost completely inhibited motility. Conserved myosin 5 and formin interaction motifs contributed to this inhibition. Consistently, mitochondrial SPIRE1 targeted myosin 5 motors and formin actin filament generators to mitochondria. Our results indicate that SPIRE1 organises an actin/myosin network at mitochondria, which opposes mitochondrial motility. Summary statementThe mitochondrial SPIRE1 protein targets myosin 5 motor proteins and formin actin-filament nucleators/elongators towards mitochondria and negatively regulates mitochondrial motility.

cell biology↗