Recombinant Saccharomyces cerevisiae ER-derived vesicles protein ERV14 (ERV14)

Introduction to Recombinant Saccharomyces cerevisiae ER-derived Vesicles Protein ERV14 (ERV14)

Saccharomyces cerevisiae ER-derived vesicles protein ERV14, commonly referred to as Erv14p, is a conserved integral membrane protein that plays a crucial role in the early secretory pathway in yeast . Belonging to a family of cargo receptors, Erv14p is essential for the selection and export of transmembrane proteins from the endoplasmic reticulum (ER) . It is localized to COPII-coated vesicles and is involved in vesicle formation and the incorporation of specific secretory cargo .

Functional Role of ERV14

Erv14p facilitates the transport of specific proteins from the ER to the Golgi apparatus by interacting with the COPII coat complex . This interaction is crucial for packaging cargo proteins into COPII vesicles, which are then transported to the Golgi .

Key functions of ERV14:

• Cargo Selection: Erv14p is required for the selective packaging of transmembrane proteins, such as Axl2p, into COPII vesicles .

• Vesicle Formation: It participates in the formation of COPII vesicles, which are essential for protein transport from the ER .

• Protein Trafficking: Erv14p ensures the correct localization of proteins to their target destinations, such as the cell surface .

ERV14 and COPII Vesicles

Erv14p interacts genetically and physically with subunits of the COPII coat, which is necessary for the export of secretory proteins from the ER . This interaction depends on conserved residues within a cytoplasmically exposed loop domain of Erv14p .

• Erv14p is enriched in COPII vesicles, indicating its direct involvement in the COPII-mediated transport pathway .

• Mutations in the loop region of Erv14p can disrupt its interaction with the COPII coat, leading to the accumulation of Erv14p-cargo complexes in the ER .

Impact of ERV14 on Mycelial Growth

Research indicates that ERV14 influences mycelial growth and protein secretion, highlighting its broader role in cellular function .

• Deletion of ERV14 in certain fungal strains leads to a reduced number of conidial peduncles and defective conidial heads .

• The absence of ERV14 delays spore germination and results in abnormal mycelial development .

Phosphorylation of ERV14

Phosphorylation of Erv14p at specific sites, such as serine 134 (S134), plays a regulatory role in its function and trafficking .

• Mimicking phosphorylation at S134 prevents the incorporation of Erv14p into COPII vesicles .

• Mutations affecting phosphorylation can alter ER structure and affect the localization of plasma membrane transporters .

ERV14 and Sporulation

During sporulation in Saccharomyces cerevisiae, Erv14p is required for prospore membrane formation . Deletion of ERV14 results in misshapen prospore membranes, indicating its role in this developmental process .

• Erv14p influences the localization of proteins, such as Sma2p, which is essential for prospore membrane morphology .

• Overexpression of the ERV14 paralog ERV15 can suppress sporulation defects in erv14 cells .

ERV14 Interactions

Erv14p interacts with several proteins involved in ER-to-Golgi transport and other cellular processes :