Work

Inactivation of the three GGA genes in HeLa cells partially compromises lysosomal enzyme sorting

Year: 2020

Type: article

Abstract: The Golgi‐localized, gamma‐ear containing, ADP‐ribosylation factor‐binding proteins (GGAs 1, 2, and 3) are multidomain proteins that bind mannose 6‐phosphate receptors (MPRs) at the Golgi and play a role, along with adaptor protein complex 1 (AP‐1), in the sorting of newly synthesized lysosomal hydrolases to the endolysosomal system. However, the relative importance of the two types of coat proteins in this process is still unclear. Here, we report that inactivation of all three GGA genes in HeLa cells decreased the sorting efficiency of cathepsin D from 97% to 73% relative to wild‐type, with marked redistribution of the cation‐independent MPR from peripheral punctae to the trans‐Golgi network. In comparison, GNPTAB−/− HeLa cells with complete inactivation of the mannose 6‐phosphate pathway sorted only 20% of the cathepsin D. We conclude that the residual sorting of cathepsin D in the GGA triple‐knockout cells is mediated by AP‐1.

Source: FEBS Open Bio

DOI: 10.1002/2211-5463.13040

Authors: Balraj Doray, Lin Liu, Wang‐Sik Lee, Benjamin C. Jennings, Stuart Kornfeld

Institution: Washington University in St. Louis

Language: English

Topic: Cellular transport and secretion

Subfield: Cell Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $1,750

Funder: National Cancer Institute