Washington University Medical Center's D. Ashley Hill published work in this week's advanced online edition of Science that implicates DICER1 mutations in development of familial pleuropulmonary blastoma (PPB), a rare pediatric lung tumor. First using a four-family linkage study, the scientists mapped the PPB locus to chromosome 14q, and from this singled out DICER1. Second, they sequenced the genomic DNA of 11 PPB families to find heterozygous germline mutations in DICER1; in 10 of these families, the mutations resulted in proteins that were truncated proximal to the two carboxy-terminal RNase III functional domains, "and thus likely cause loss of function" and tumorigenesis, says the paper.
Benoît Kornmann at UCSF designed an experiment using a synthetic biology screen to find proteins involved in mitochondria/ER junctions. Screening for mutants that could be "complemented by a synthetic protein designed to artificially tether the two organelles," says the abstract, he and his team discovered that the Mmm1/Mdm10/Mdm12/Mdm34 complex could bind the two together. Genome-wide interaction maps showed that the proteins in the complex were associated with phospholipid synthesis and calcium signaling genes.
In the print edition this week, there's a special focus on stem cells, including this review of NIH's draft guidelines on stem cell research by Mary Majumder and Cynthia Cohen. The authors say that while the effort is positive, there are certain omissions and concerns about how the guidelines would affect ongoing research in the field.
There's also a paper on the evolution of diatoms, which appear to have recruited genes from both red and green algae "to forge a highly successful, species-rich protist lineage," according to the abstract. Lead authors Ahmed Moustafa and Bánk Beszteri used a genome-wide screen to assess the nuclear gene content that came from green algae. There's a perspective piece on the paper, as well as a news report from our sister publication GenomeWeb Daily News.
A paper from senior author Martha Bulyk demonstrates the use of microarrays to study the binding specificities of more than 100 DNA binding proteins in mouse. The result was that "virtually every protein analyzed possessing unique preferences," the authors write, noting that this challenges "our molecular understanding of how proteins interact with their DNA binding sites."