Fig 1.
Interaction of multivalent molecules leading to LLPS.
At constant environmental conditions (e.g., temperature, ionic strength, pH), the propensity of a multivalent scaffold protein to undergo LLPS only depends on its concentration. Crossing the protein’s specific concentration threshold (dashed line) leads to droplet formation resulting in a qualitative change upon a small, linear quantitative change. Created with Biorender.com. LLPS, liquid–liquid phase separation.
Fig 2.
Maturation of viral replication compartments.
(A) The nucleus contains membrane-less compartments such as Nuc, CBs, PML-NBs (PNB), and RCs of DNA viruses. In the case of HCMV [25], early RCs exhibit fluid properties consistent with being formed by LLPS. After the onset of viral DNA replication, these properties change, resulting in the hardening of late RCs. (B) Hypothetical model. In early RCs, weak and transient interactions predominate, resulting in fluid properties (left). In late RCs, the increased quantity of viral DNA, accumulation of client proteins, and posttranslational modifications of the scaffold proteins may result in tighter interactions of the molecules and the formation of more ordered molecular assemblies (right). Created with Biorender.com. CB, Cajal body; HCMV, human cytomegalovirus; LLPS, liquid–liquid phase separation; Nuc, nucleoli; PML-NB, promyelocytic leukemia nuclear body; RC, replication compartment.