Functional differentiation of Sec13 paralogues in the euglenozoan protists

TY - JOUR

T1 - Functional differentiation of Sec13 paralogues in the euglenozoan protists

AU - Drahomíra, Faktorová

AU - Záhonová, Kristína

AU - Benz, Corinna

AU - Dacks, Joel B.

AU - Field, Mark

AU - Lukeš, Julius

N1 - Funding Information: This work was supported by grants from Czech Grant Agency No. 23-06479X (to J.L.), the Gordon and Betty Moore Foundation GBMF9354 (to J.L.), the Wellcome Trust 204697/Z/16/Z (to M.C.F.), and the Czech Bioimaging grant LM2018129. Computational resources were provided by the eINFRA CZ project (ID: 90140).

PY - 2023/6/14

Y1 - 2023/6/14

N2 - The β-propeller protein Sec13 plays roles in at least three distinct processes by virtue of being a component of the COPII endoplasmic reticulum export vesicle coat, the nuclear pore complex (NPC) and the Seh1-associated (SEA)/GATOR nutrient-sensing complex. This suggests that regulatory mechanisms coordinating these cellular activities may operate via Sec13. The NPC, COPII and SEA/GATOR are all ancient features of eukaryotic cells, and in the vast majority of eukaryotes, a single Sec13 gene is present. Here we report that the Euglenozoa, a lineage encompassing the diplonemid, kinetoplastid and euglenid protists, possess two Sec13 paralogues. Furthermore, based on protein interactions and localization studies we show that in diplonemids Sec13 functions are divided between the Sec13a and Sec13b paralogues. Specifically, Sec13a interacts with COPII and the NPC, while Sec13b interacts with Sec16 and components of the SEA/GATOR complex. We infer that euglenozoan Sec13a is responsible for NPC functions and canonical anterograde transport activities while Sec13b acts within nutrient and autophagy-related pathways, indicating a fundamentally distinct organization of coatomer complexes in euglenozoan flagellates.

AB - The β-propeller protein Sec13 plays roles in at least three distinct processes by virtue of being a component of the COPII endoplasmic reticulum export vesicle coat, the nuclear pore complex (NPC) and the Seh1-associated (SEA)/GATOR nutrient-sensing complex. This suggests that regulatory mechanisms coordinating these cellular activities may operate via Sec13. The NPC, COPII and SEA/GATOR are all ancient features of eukaryotic cells, and in the vast majority of eukaryotes, a single Sec13 gene is present. Here we report that the Euglenozoa, a lineage encompassing the diplonemid, kinetoplastid and euglenid protists, possess two Sec13 paralogues. Furthermore, based on protein interactions and localization studies we show that in diplonemids Sec13 functions are divided between the Sec13a and Sec13b paralogues. Specifically, Sec13a interacts with COPII and the NPC, while Sec13b interacts with Sec16 and components of the SEA/GATOR complex. We infer that euglenozoan Sec13a is responsible for NPC functions and canonical anterograde transport activities while Sec13b acts within nutrient and autophagy-related pathways, indicating a fundamentally distinct organization of coatomer complexes in euglenozoan flagellates.

KW - Diplonema

KW - Euglenozoa

KW - coatomer

KW - membrane trafficking

KW - Sec13

KW - nuclear pore complex

KW - SEA/GATOR complex

KW - paralog expansion

KW - paralogue expansion

UR - https://www.scopus.com/pages/publications/85161868725

U2 - 10.1098/rsob.220364

DO - 10.1098/rsob.220364

M3 - Article

C2 - 37311539

SN - 2046-2441

VL - 13

JO - Open Biology

JF - Open Biology

IS - 6

M1 - 220364

ER -