C-terminal tagging, transmembrane domain hydrophobicity, and an ER retention motif influence the secretory trafficking of the inner nuclear membrane protein emerin.

ABSTRACT: The inner nuclear membrane (INM), a subdomain of the endoplasmic reticulum (ER), sequesters hundreds of transmembrane proteins within the nucleus. We previously found that one INM protein, emerin, can evade the INM by secretory transport to the lysosome, where it is degraded (Buchwalter et al., 2019). In this work, we used targeted mutagenesis to identify intrinsic sequences that promote or inhibit emerin's secretory trafficking. By manipulating these sequences across several tag and expression level combinations, we now find that emerin's localization is sensitive to C-terminal GFP tagging. While emerin's long, hydrophobic C-terminal transmembrane domain facilitates trafficking to the lysosome, extending its lumenal terminus with a GFP tag biases the protein toward this pathway. In contra

SUBMITTER: Mella J 

PROVIDER: S-EPMC12393879 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature