In a Science paper published online in advance this week, researchers in China show that loss-of-function mutations in PSENEN, PSEN1, or NCSTN — which encode components of the γ-secretase multiprotein complex — are associated with hidradenitis suppurativa, commonly known as familial acne inversa. The team found these independent mutations in their screen of six Chinese families with features of acne inversa and related clinical sympotoms. The investigators suggest that their findings "implicate the γ-secretase-Notch pathway in the molecular pathogenesis of AI," they write, noting that "it is well known that mutations in the two presenilin genes (PSEN1 and PSEN2), but not the other γ-secretase component genes, cause early-onset familial [Alzheimer's disease] and non-Alzheimer dementias."
In another advance online publication, investigators in Australia report that "Mcl-1 is essential for germinal center formation and B cell memory." By deleting genes encoding anti-apoptotic molecules Mcl1 and Bcl2l1 in an "inducible system synchronized with expression of activation-induced cytidine deaminase following immunization," the team found that the resulting limited expression of Mc11 "reduced the magnitude of the GC response with an equivalent, but not greater, effect on memory B cell formation," according to the paper. The team suggests that its data implicat Mc11 as "the main anti-apoptotic regulator of activated B cell survival."
Researchers in Tokyo show that "the phosphorylation of histone H3-threonine 3 mediated by Haspin cooperates with Bub1-mediated histone 2A-serine 121 phosphorylation in targeting" the chromosomal passenger complex to the inner centromere in both fission yeast and human cells. H3-pT3, the authors report, "promotes nucleosome binding of surviving," while phosphorylated H2A-S121 enables shugoshin-binding.
In two news articles published this week, Science's John Travis documents Sitting Bull's great-grandson's partnership with the University of Copenhagen's Eske Willerslev to analyze DNA from a sample of the renowned Lakota warrior's hair. Ernie LaPointe reached out to Willerslev three years ago in an effort to conclusively identify his great-grandfather's remains, and "solidify our connection to" Sitting Bull through genetic analysis. The University of New Mexico's Keith Hunley told Science that "it's just a single genome, but as a reference, it's valuable. … As long as there is no European ancestry in that lineage, it's a window into the deep past."