Negative charge in the RACK1 loop broadens the translational capacity of the human ribosome.

Although the roles of initiation factors, RNA binding proteins, and RNA elements in regulating translation are well defined, how the ribosome functionally diversifies remains poorly understood. In their human hosts, poxviruses phosphorylate serine 278 (S) at the tip of a loop domain in the small subunit ribosomal protein RACK1, thereby mimicking negatively charged residues in the RACK1 loops of dicot plants and protists to stimulate translation of transcripts with 5' poly(A) leaders. However, how a negatively charged RACK1 loop affects ribosome structure and its broader translational output is not known.

Human Cytomegalovirus Exploits TACC3 To Control Microtubule Dynamics and Late Stages of Infection.

While it is well established that microtubules (MTs) facilitate various stages of virus replication, how viruses actively control MT dynamics and functions remains less well understood. Recent work has begun to reveal how several viruses exploit End-Binding (EB) proteins and their associated microtubule plus-end tracking proteins (+TIPs), in particular to enable loading of viral particles onto MTs for retrograde transport during early stages of infection. Distinct from other viruses studied to date, at mid- to late stages of its unusually protracted replication cycle, human cytomegalovirus (HCMV) increases the expression of all three EB family members.

Proteomic and mechanistic dissection of the poxvirus-customized ribosome.

Ribosomes are often viewed as protein synthesis machines that lack intrinsic regulatory capacity. However, studies have established that ribosomes can functionally diversify through changes in the composition of, or post-translational modifications to ribosomal subunit proteins (RPs). We recently found that poxviruses phosphorylate unique sites in the RP, receptor for activated C kinase 1 (RACK1) to enhance viral protein synthesis.