Isoform-selective Oligomer Formation of Saccharomyces cerevisiae p24 Family Proteins

Abstract

Background: p24 family proteins function as cargo receptors for ER-Golgi transport. Results: Genetic and physical interactions among eight known and one newly identified S. cerevisiae p24 proteins were determined. Conclusion: Yeast p24 proteins function in several functionally redundant complexes, including one containing a novel p24 isoform induced under respiratory conditions. Significance: This is the first comprehensive study of the yeast p24 complexes.

Drosophila p24 and Sec22 regulate Wingless trafficking in the early secretory pathway

“…Previous study in yeast uncovered that the different p24 sub-family members form diverse complexes, thus playing multiple roles in escorting cargoes [31]. Consistent with the yeast work, we found that different p24 proteins play different roles and cannot be replaced by each other, indicating the functional diversity of the p24 family.…”

“…Several p24 proteins, including Baiser, CHOp24, Eclair, Opm and p24-1 [16,17], are involved in this process. These p24 family members are functionally diverse and cannot be replaced by each other, probably function in a partially redundant manner and/or by forming diverse complexes [31]. …”

“…Early studies in yeast have revealed that yeast p24 proteins form functionally redundant αβγδ complexes [31]. In the study of p24 proteins escorting Wg/Wnt, Buechling found that several p24 proteins may contribute in a partially redundant manner [32].…”

COPII Coat Composition Is Actively Regulated by Luminal Cargo Maturation

“…The p24 proteins assemble in a heteromeric complex that cycles between the ER and Golgi compartments [16,[18][19][20][21]. Experimental evidence from yeast and mammalian cell systems suggests a specific role of the p24 complex as a transmembrane adaptor or cargo receptor that could link remodeled GPI-APs to the cytosolic COPII coat, ensuring their selective incorporation into nascent COPII vesicles [10][11][12].…”

The α-Helical Region in p24γ2 Subunit of p24 Protein Cargo Receptor Is Pivotal for the Recognition and Transport of Glycosylphosphatidylinositol-anchored Proteins

“…1D). Redundancy among p24␣ and p24␥ proteins had been described recently in yeast (11). Because the GPI-AP transport was impaired in p24␥ 2 knockdown cells and could not be compensated by the slight overexpression of other p24␥ proteins (Fig.…”