Transmission and immunity: the importance of heterogeneity in the fight against malaria.

The complex relationship between transmission and parasite prevalence in humans is an important issue. Using a large dataset matching estimates of malaria transmission and Plasmodium falciparum prevalence in African children, a stimulating study published in Nature provides evidence that heterogeneity in susceptibility crucially determines the prevalence of infection. Moreover, it suggests that children who clear infections are not immune to new infections, irrespective of the amount of transmission.

[Epigenetics and cancer].

The term epigenetics encompasses all the modifications that are stable across cell generations, but which do not imply any change in DNA sequence. Post-translational modifications of the histones and DNA methylation are the most studied types of epigenetic information due to their major impact on transcription. The link between epigenetics and cancer arises from the fact that epigenetic deregulations frequently participate in tumorigenesis by inactivation of tumour-suppressor genes.

A family of human zinc finger proteins that bind methylated DNA and repress transcription.

In vertebrates, densely methylated DNA is associated with inactive transcription. Actors in this process include proteins of the MBD family that can recognize methylated CpGs and repress transcription. Kaiso, a structurally unrelated protein, has also been shown to bind methylated CGCGs through its three Krüppel-like C2H2 zinc fingers.

The human enhancer blocker CTC-binding factor interacts with the transcription factor Kaiso.

CTC-binding factor (CTCF) is a DNA-binding protein of vertebrates that plays essential roles in regulating genome activity through its capacity to act as an enhancer blocker. We performed a yeast two-hybrid screen to identify protein partners of CTCF that could regulate its activity. Using full-length CTCF as bait we recovered Kaiso, a POZ-zinc finger transcription factor, as a specific binding partner.