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Biology subjects

Jackson, Z.

Publications and source records attributed to Jackson, Z..

3 recordsLinked to original sources

HOP/STIP1 is required for KSHV lytic replication.

Kaposi sarcoma associated herpesvirus (KSHV) is a DNA virus that causes Kaposi sarcoma, a cancer of endothelial origin. KSHV uses the activity of host molecular chaperones like Hsp70 and Hsp90 for the folding of host and viral proteins required for productive infection. Hsp70 and Hsp90 chaperones form proteostasis networks with several regulatory proteins known as co-chaperones. Of these, Hsp90-Hsp70 organising protein (HOP) is an early-stage co-chaperone that regulates transfer of folding substrate proteins between the Hsp70 and Hsp90 chaperone systems. While roles for Hsp90 and Hsp70 in KSHV biology have been described, HOP has not previously been studied in this context despite its prominent interaction with both chaperones. Here we demonstrate a novel function for HOP as a new host factor required for effective lytic replication of KSHV in primary effusion cell lines. Data summaryThe authors confirm all supporting data, code and protocols have been provided within the article or through supplementary data files.

microbiology↗

Dynamic trait distribution as a source for shifts in interaction strength and population density

Intraspecific trait variation has been increasingly recognized as an important factor in determining species interaction and diversity. Eco-evolutionary models have studied the distribution of trait values within a population that changes over the generations as a result of selection and heritability. Non-heritable traits that can change within the lifetime, such as behavior, can cause trait-mediated indirect effects, often studied by modeling the dynamics of a homogeneous trait. Complementary to these two approaches, we study the distribution of traits within a population and its dynamics on short timescales due to ecological processes. We consider several mechanisms by which the trait distribution can shift dynamically: phenotypic plasticity within each individual, differential growth among individuals, and preferential consumption by the predator. Through a simple predator-prey model that explicitly tracks the trait distribution within the prey, we illustrate some unusual consequences of trait shifts, including the healthy herd effect and the emergent promotion of the prey by the predator. We analyze the cause of these phenomena by identifying the density and trait effects from the predator. Our results show that intraspecific trait variation and the dynamics of its distribution can lead to the modification of species interactions and result in outcomes that are otherwise unexpected.

ecology↗

Heterogeneity of Interaction Strengths and Its Consequences on Ecological Systems

Ecosystems are formed by networks of species and their interactions. Traditional models of such interactions assume a constant interaction strength between a given pair of species. However, there is often significant trait variation among individual organisms even within the same species, causing heterogeneity in their interaction strengths with other species. The consequences of such heterogeneous interactions for the ecosystem have not been studied systematically. As a theoretical exploration, we analyze a simple ecosystem with trophic interactions between two predators and a shared prey, which would exhibit competitive exclusion in models with homogeneous interactions. We consider several scenarios where individuals of the prey species differentiate into subpopulations with different interaction strengths. We show that in all these cases, whether the heterogeneity is inherent, reversible, or adaptive, the ecosystem can stabilize at a new equilibrium where all three species coexist. Moreover, the prey population that has heterogeneous interactions with its predators reaches a higher density than it would without heterogeneity, and can even reach a higher density in the presence of two predators than with just one. Our results suggest that heterogeneity may be a naturally selected feature of ecological interactions that have important consequences for the stability and diversity of ecosystems.

ecology↗