Protein Kinase D2 Assembles a Multiprotein Complex at the Trans-Golgi Network to Regulate Matrix Metalloproteinase...

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Vesicle formation and fission at the trans-Golgi network (TGN) are crucial for constitutive secretion.
• Adenosyl-ribosylation factor (ARF) proteins and protein kinase D (PKD) family kinases regulate these TGN processes.
• The precise functional link between ARF and PKD proteins in TGN-mediated transport remained unclear.

Purpose of the Study:

• To elucidate the functional relationship between ARF and PKD protein families in regulating protein transport from the TGN.
• To identify novel protein complexes involved in constitutive secretion at the TGN.
• To characterize the role of protein kinase D2 (PKD2) in the assembly of regulatory complexes at the TGN.

Main Methods:

• Demonstration of a novel functional protein complex assembly at the TGN.
• Investigation of the interactions between cytosolic PKD2, ARF-like GTPase (ARL1), Arfaptin2, and ARF1.
• Analysis of the requirement of PKD2 and ARL1 for the formation of a multiprotein complex involving ARF1 and Arfaptin2.

Main Results:

• Cytosolic PKD2 binds and shuttles ARL1 to the TGN.
• ARL1 facilitates the localization of Arfaptin2 to the TGN.
• PKD2 and ARL1 are essential for assembling a complex of ARF1 and Arfaptin2 at the TGN.
• This complex is critical for the secretion of matrix metalloproteinase-2 and -7.

Conclusions:

• PKD2 acts as a central factor in forming a multiprotein complex at the TGN.
• This complex governs the constitutive secretion of matrix metalloproteinase cargo.
• The findings reveal a novel mechanism linking PKD2, ARL1, ARF1, and Arfaptin2 in regulating TGN-mediated secretion.