Physiological coreceptor use by dual-tropic HIV-1: one plus one equals one

Physiological coreceptor use by dual-tropic HIV-1: one plus one equals one.

Meiotic Spindle Self-Organization: One Plus One Equals Only One

Like other cellular organelles, the bipolar spindle is a structure of well-defined size and shape. Now, spindle fusion experiments using micro-manipulation have allowed current models for spindle morphogenesis and size control to be tested.

One sequence plus one mutation equals two folds.

I n this issue of PNAS, Alexander et al. (1) report an observation that will be a topic of heated discussion among biochemists for a long time to come. A single amino acid substitution can, in the right context, completely change the fold of a protein. And the structural change produced by this one mutation cannot be dismissed as a semantic issue over what constitutes a different fold. As shown...

In the Gut’s Microbial Community, One Plus One Equals Many (Effects)

December 2006 | Volume 4 | Issue 12 | e418 Most governments around the world set conservation policy based on the assumption that resource exploitation and species protection can co-exist in the same place. These policies have led to Orwellian “marine protected areas” that host commercial fi shing operations, leading one to wonder who’s protecting whom. A new study reveals the danger of this ap...

Preferential coreceptor utilization and cytopathicity by dual-tropic HIV-1 in human lymphoid tissue ex vivo.

Many HIV-1 isolates at the late stage of disease are capable of using both CXCR4 and CCR5 in transfected cell lines, and are thus termed dual-tropic. Here we asked whether these dual-tropic variants also use both coreceptors for productive infection in a natural human lymphoid tissue microenvironment, and whether use of a particular coreceptor is associated with viral cytopathicity. We used 3 c...