Objectives

The proposed projects will focus on exploring the mechanisms how reversible posttranslational modifications including phosphorylation, glycosylation, palmitoylation or ubiquitination govern the orchestrated functioning of membrane transporters and enzymes in calcifying cells of the sea urchin larva. In particular, identification of cAMP mediated posttranslational modifications of key membrane transporters like the proton channel Otop2l or the bicarbonate transporter Sp-Slc4a10 that exhibit phosphorylation and glycosylation motifs will be a core task of this project. Here special attention will be dedicated to cAMP-dependent protein kinase A-mediated phosphorylation/dephosphorylation cycles that can modulate glycosyltransferase to regulate N-gylcosylation of membrane proteins. The cellular mineralization process involves dynamic subcellular trafficking of vesicles resembling macropinosomes, that contain transporters (Sp-Slc4a10; Cara7) and channels (Otop2L) localized in their membranes. Thus, a second part of this project will address potential modulations of membrane transporters during the macropinocytosis process. 

Aim i)   Unravel the cAMP-dependent regulatory cascade underlying PTMs in membrane transporters of cal              cifying cells

Aim ii)  Establishing fusion-reporter proteins for in vivo tracking of membrane transporters in the animal                      model

Aim iii) Identification of protein trafficking mechanisms underlying the mineralization process