ACBD3 Interaction with TBC1 Domain 22 Protein Is Differentially Affected by Enteroviral and Kobuviral 3A Protein BindingAlexander L. Greninger, Giselle M. Knudsen, Miguel Betegon, Alma L. Burlingame, Joseph L. DeRisi
mBio, 2013Abstract: Despite wide sequence divergence, multiple picornaviruses use the Golgi adaptor acyl coenzyme A (acyl-CoA) binding
domain protein 3 (ACBD3/GCP60) to recruit phosphatidylinositol 4-kinase class III beta (PI4KIII/PI4KB), a factor required
for viral replication. The molecular basis of this convergent interaction and the cellular function of ACBD3 are not fully understood.
Using affinity purification-mass spectrometry, we identified the putative Rab33 GTPase-activating proteins TBC1D22A
and TBC1D22B as ACBD3-interacting factors. Fine-scale mapping of binding determinants within ACBD3 revealed that the interaction
domains for TBC1D22A/B and PI4KB are identical. Affinity purification confirmed that PI4KB and TBC1D22A/B interactions
with ACBD3 are mutually exclusive, suggesting a possible regulatory mechanism for recruitment of PI4KB. The
C-terminal Golgi dynamics (GOLD) domain of ACBD3 has been previously shown to bind the 3A replication protein from Aichi
virus. We find that the 3A proteins from several additional picornaviruses, including hepatitis A virus, human parechovirus 1,
and human klassevirus, demonstrate an interaction with ACBD3 by mammalian two-hybrid assay; however, we also find that the
enterovirus and kobuvirus 3A interactions with ACBD3 are functionally distinct with respect to TBC1D22A/B and PI4KB recruitment.
These data reinforce the notion that ACBD3 organizes numerous cellular functionalities and that RNA virus replication
proteins likely modulate these interactions by more than one mechanism.
