Long-term RNA persistence in postmortem contexts.

Ribonucleic acids (RNA) are generally considered fragile molecules that are readily degraded. However, there is growing documentation of long-term (from days to centuries) RNA persistence in a variety of contexts and tissue types, and as such a number of academic disciplines are beginning to exploit degraded RNA. While the reasons for its survival are not fully understood, there are several plausible mechanisms that would safeguard this molecule against degradation.

Assessing the extent of bone degradation using glutamine deamidation in collagen.

Collagen peptides are analyzed using a low-cost, high-throughput method for assessing deamidation using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). For each chosen peptide, the theoretical distribution is calculated and the measured distribution for each sample compared with this to determine the extent of glutamine deamidation. The deamidation of glutamine (Q) to glutamic acid (E) results in a mass shift of +0.

Site-specific deamidation of glutamine: a new marker of bone collagen deterioration.

Rationale: Non-enzymatic deamidation accumulates in aging tissues in vivo and has been proposed to be potentially useful as a molecular clock. The process continues post mortem, and here we explore the increase in levels of deamidation in archaeological collagen, as measured during Zooarchaeology by Mass Spectrometry (ZooMS) analysis.

Methods: With the high sensitivity of current generation mass spectrometers, ZooMS provides a non-destructive and highly cost-effective method to characterise collagen peptides.

Bone marrow and bone as a source for postmortem RNA.

The susceptibility of RNA to enzymatic degradation has been considered as a tool to estimate time-since-death in forensic samples, and it has previously been demonstrated that the choice of tissue is an important factor. In this study we have extracted RNA from decaying bone and bone marrow under the hypothesis that the delayed onset of putrefaction may render them a useful source in this context. In a preliminary study, total RNA was extracted from bone and bone marrow that had been sampled from six skeletally mature rabbits at time points between zero and 31 days after death.

Cartilage-hair hypoplasia-associated mutations in the RNase MRP P3 domain affect RNA folding and ribonucleoprotein assembly.

Cartilage-hair hypoplasia (CHH) is caused by mutations in the gene encoding the RNA component of RNase MRP. Currently it is unknown how these mutations affect the function of this endoribonuclease. In this study we investigated the effect of mutations in the P3 domain on protein binding and RNA folding.

Heterodimerization regulates RNase MRP/RNase P association, localization, and expression of Rpp20 and Rpp25.

Rpp20 and Rpp25 are subunits of the human RNase MRP and RNase P endoribonucleases belonging to the Alba superfamily of nucleic acid binding proteins. These proteins, which bind very strongly to each other, transiently associate with RNase MRP. Here, we show that the Rpp20-Rpp25 heterodimer is resistant to both high concentrations of salt and a nonionic detergent.