Multiple golgins are required to support extracellular matrix secretion, modification, and assembly.

Area of Science:

• Cell Biology
• Biochemistry
• Molecular Biology

Background:

• Extracellular matrix (ECM) protein secretion is essential for tissue health.
• Dysfunction of the Golgi apparatus, a key organelle in protein processing and secretion, is linked to connective tissue disorders.

Purpose of the Study:

• To investigate the roles of Golgi organizing proteins GMAP210 and Golgin-160 in ECM secretion.
• To understand the specific contributions of these proteins to Golgi organization and ECM biogenesis.

Main Methods:

• CRISPR-Cas9 gene editing was used to create knockout cell lines for GMAP210 and Golgin-160.
• Golgi organization was assessed using microscopy.
• ECM protein secretion and synthesis were analyzed, including collagen organization and glycosaminoglycan production.
• Proteomics was employed to identify changes in secreted ECM proteins.

Main Results:

• Golgin-160 knockout led to Golgi fragmentation and vesicle accumulation.
• GMAP210 loss resulted in cisternal fragmentation, dilation, and tubulovesicular structure accumulation.
• Both proteins were essential for proper fibrillar collagen organization and glycosaminoglycan synthesis, indicating distinct functions.
• Proteomics revealed both overlapping and unique changes in ECM protein secretion profiles between the two knockouts.

Conclusions:

• GMAP210 and Golgin-160 play nonredundant roles in maintaining Golgi structure and function for ECM secretion.
• These Golgi proteins collectively establish the necessary environment for efficient ECM protein secretion, modification, and assembly.
• This study provides the first evidence that Golgin-160 is required for extracellular matrix secretion.