Localized Phosphorylation of a Kinesin-1 Adaptor by a Capsid-Associated Kinase Regulates HIV-1 Motility and Uncoating

Abstract

Summary Although microtubule motors mediate intracellular virus transport, the underlying interactions and control mechanisms remain poorly defined. This is particularly true for HIV-1 cores, which undergo complex, interconnected processes of cytosolic transport, reverse transcription and uncoating of the capsid shell. Although kinesins have been implicated in regulating these events, curiously there are no direct kinesin-core interactions. We recently showed that the capsid-associated kinesin-1 adaptor protein, fasciculation and elongation protein zeta-1 (FEZ1) regulates HIV-1 trafficking. Here, we show that FEZ1 and kinesin-1 heavy, but not light chains regulate not only HIV-1 transport, but also uncoating. This required FEZ1 phosphorylation, which controls its interaction with kinesin-1. HIV-1 did not stimulate widespread FEZ1 phosphorylation, but instead bound MT affinity-regulating kinase 2 (MARK2) to stimulate FEZ1 phosphorylation on viral cores. Our findings reveal that HIV-1 binds a regulatory kinase to locally control kinesin-1 adaptor function on viral cores, thereby regulating both particle motility and uncoating.

Microtubule Retrograde Motors and Their Role in Retroviral Transport

“…The second model proposes that capsid undergoes structural changes in the cytoplasm resulting in capsid rupture where a portion of capsid remains intact until disassembly is completed at the nuclear pore, this model agrees with the idea that during trafficking along microtubules, cytoplasmic dynein and kinesin 1, particularly Kif5B, are required for this process as the genetic inhibition of DHC and Kif5B by siRNA, or pharmacological inhibition of dynein function, delayed uncoating, and reduced HIV-1 infection [33]. Furthermore, FEZ1 a kinesin adaptor that bridge HIV-1 cores to Kif5B is important for both traffic and uncoating [31][32][33], were phosphorylation of FEZ1 is required to recruit Kif5B to the HIV-1 cores and to mediate uncoating along movement [32]. If FEZ1 and Kif1B promote uncoating and BicD2 protect from accelerated uncoating and/or rapidly move HIV-1 PIC to the nuclear pore area [28], there must be a highly regulated balance that couples trafficking with uncoating to allow sufficient loss of capsid to permit nuclear entry, but a such a rate that viral DNA is not detected by the antiviral machinery in the cytoplasm.…”

“…-Kinesin-1 adaptor, FEZ1 has been shown to regulate early transport of viral particles by associating to HIV-1 capsid [31]. -Kinesin might also play a role in uncoating of HIV-1 thanks to FEZ1 and Kif5B [32,33].…”

“…This bi-directional movement is also important for uncoating (loss of capsid). Uncoating is a highly regulated process necessary for nuclear entry, no uncoating or accelerated uncoating are deleterious for infection [32,44,[59][60][61]. Although it is not clear how the mature capsid core disassembles to allow the nuclear translocation of the lentiviral genomes, two models have been debated.…”

Cytoplasmic CPSF6 regulates HIV-1 capsid trafficking and infection in a cyclophilin A-dependent manner

“…Previously it was shown that HIV-1 capsid traffics on microtubules on its way to the nucleus (Dharan and Campbell, 2018). HIV-1 capsid uncoating is delayed by destabilization of microtubules or knockdown of microtubule motor proteins kinesin and dynein or NPC protein Nup358 (Dharan et al, 2016;Lukic et al, 2014;Malikov and Naghavi, 2017), suggesting that microtubule trafficking and NPC binding is linked to capsid uncoating. Recent work from several groups suggests that the main uncoating event occurs at or inside the nucleus (Arhel et al, 2007;Burdick et al, 2017;Burdick et al, 2020;Francis and Melikyan, 2018;Zurnic Bonisch et al, 2020).…”

“…An important yet understudied aspect of HIV-1 infection, which is referred to as uncoating, describes the process of capsid dissociation that occurs during reverse transcription and before viral DNA integration into host chromatin (Ambrose and Aiken, 2014;Campbell and Hope, 2015). HIV-1 capsid uncoating is dependent on microtubule trafficking (Lukic et al, 2014;Malikov and Naghavi, 2017;Pawlica and Berthoux, 2014) and may occur in a multi-step process (Xu et al, 2013).…”