Open AccessConcerted regulation of actin polymerization during constitutive secretion by Cortactin and PKD2
Author(s) -
Florian Weeber,
Alexander Becher,
Tanja Seibold,
Thomas Seufferlein,
Tim Eiseler
Publication year - 2019
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.232355
Subject(s) - cortactin , biology , microbiology and biotechnology , actin , phosphorylation , biochemistry , cytoskeleton , cell
Constitutive secretion from the trans-Golgi-network (TGN) is facilitated by a concerted regulation of vesicle biogenesis and fission processes. The Protein kinase D family (PKD) has been previously described to enhance vesicle fission by modifying the lipid environment. PKD also phosphorylates the actin regulatory protein Cortactin at S298 to impair synergistic actin polymerization. We here report additional functions for PKD2 and Cortactin in the regulation of actin polymerization during the fission of transport carriers from the TGN. Phosphorylation of Cortactin at S298 impairs the interaction between WIP and Cortactin. WIP stabilizes the autoinhibited conformation of N-WASP. This leads to an inhibition of synergistic Arp2/3-complex-dependent actin polymerization at the TGN. PKD2 activity at the TGN is controlled by active CDC42-GTP which directly activates N-WASP, inhibits PKD2 and shifts the balance to non-S298-phosphorylated Cortactin to take-over WIP from N-WASP. Consequently, synergistic actin polymerization at the TGN and constitutive secretion were enhanced.