Biology subjects

Lagunas-Gomez, D.

Publications and source records attributed to Lagunas-Gomez, D..

3 recordsLinked to original sources

bioRxiv2024

The chloroplast located HKT transporter plays an important role in sporophyte development in Physcomitrium patens

Cell survival depends on the maintenance of cell homeostasis that involves all the biochemical, genomic and transport processes that take place in all the organelles within an eukaryote cell. In particular, ion homeostasis is required to regulate the membrane potential and solute transport across all membranes, any alteration in these parameters will reflect in the malfunctioning of any organelle. In plant cells, sodium transporters play a central role in keeping the concentrations of this cation across all membranes under physiological conditions to prevent its toxic effects. HKT transporters are a family of membrane proteins exclusively present in plants, with some homologs being present in prokaryotes. HKT transporters have been associated to salt tolerance in plants, retrieving any leak of the cation into the xylem, or removing it from aerial parts to be transported to the roots along the phloem. This function has been assigned as most of the HKT transporters are located at the plasma membrane. Here, we report the localization of the moss HKT from Physcomitrium patens to the thylakoid membrane, and its mutation that leads to several alterations in the phenotype of the organism, together with the changes in expression of close to 1000 genes. Down regulation of photosynthesis related genes and the upregulation of glycolysis/respiration and ion transport genes help to explain the observed phenotype.

plant biology↗

bioRxiv2022

A cornichon protein controls polar localization of the PINA auxin transporter in Physcomitrium patens

Newly synthesized membrane proteins pass through the secretory pathway starting at the endoplasmic reticulum and packaged into COPII vesicles to continue to the Golgi apparatus before reaching their membrane of residence. It is known that cargo receptor proteins form part of the COPII complex and play a role in the recruitment of cargo proteins for their subsequent transport through the secretory pathway. The role of cornichon proteins is conserved from yeast to vertebrates, but it is poorly characterized in plants. To study the role of this protein in cellular traffic mechanisms in plants, the moss Physcomitrium patens has been selected since it can be studied at the single-cell level. Here, we studied the role of the two moss cornichon homologs in the secretory pathway. Mutant analyzes revealed that cornichon genes regulate different growth processes during the moss life cycle, by controlling auxin transport; with CNIH2 functioning as a specific cargo receptor for the auxin efflux carrier PINA, with the C-terminus of the receptor regulating the interaction and trafficking of PINA.

plant biology↗

bioRxiv2022

The C-terminus of the cargo receptor Erv14p affects COPII vesicle formation and cargo delivery

The endoplasmic reticulum (ER) is the start site of the secretory pathway, where newly synthesized secreted and membrane proteins are packaged into COPII vesicles through direct interaction with the COPII coat or aided by specific cargo receptors. Little is known about how post-translational modification events regulate packaging of cargo into COPII vesicles. Erv14/Cornichon belongs to a conserved family of cargo receptors required for the selection and ER export of transmembrane proteins. In this work, we show the importance of a phosphorylation consensus site (Serine-134) at the C-terminus of Erv14. Mimicking phosphorylation of S134 (S134D) prevents the incorporation of Erv14 into COPII vesicles, delays cell growth, exacerbates growth of sec mutants, modifies ER structure, and affects localization of several plasma membrane transporters. In contrast, the dephosphorylated mimic (S134A) had less deleterious effects, but still modifies ER structure and slows cell growth. Our results suggest that a possible cycle of phosphorylation and dephosphorylation is important for the correct functioning of Erv14p. Summary statementErv14 C-terminus regulates COPII formation and cargo delivery

cell biology↗