Sequence requirements for Hid binding and apoptosis regulation in the baculovirus inhibitor of apoptosis Op-IAP. Hid binds Op-IAP in a manner similar to Smac binding of XIAP.

It has been suggested that the Drosophila Hid protein interacts with the baculovirus Op-IAP protein in a manner similar to that of human Smac binding to XIAP, based largely on amino acid sequence homology. However, there is little direct experimental evidence in support of this hypothesis; indeed, evidence exists from previous studies suggesting that the mode of binding is not similar. We have now precisely mapped the interaction between Hid and Op-IAP, and we show clearly for the first time that the biochemical interactions between the amino terminus of Hid and BIR2 of Op-IAP are highly similar to those found between the processed amino terminus of Smac and BIR3 of XIAP. Also similar to Smac, the amino terminus of Hid must be processed to bind Op-IAP. In addition, our data also suggest that a second interaction between Hid and Op-IAP exists that does not involve the amino terminus of Hid, which may explain some of the earlier contradictory results. The evolutionary conservation of this mechanism of binding underscores its importance in apoptotic regulation. Nevertheless, interaction with Hid is not sufficient for Op-IAP to inhibit apoptosis induced by Hid overexpression or by treatment with actinomycin D, indicating that additional sequence elements are required for the anti-apoptotic function of Op-IAP.     

The effects of in vivo acclimation temperature on the fatty acid composition of channel catfish (Ictalurus punctatus) peripheral blood cells

Channel catfish were acclimated in vivo to 12, 17, 22 or 27 degrees C and their peripheral blood erythrocytes, thrombocytes, T lymphocytes and B lymphocytes assayed for cellular fatty acid composition. Excepting cells from 12 degrees C acclimated fish, all cells responded to acclimation to lower temperatures by exhibiting increased levels of phospholipid unsaturated fatty acids. Although temperature independent differences were observed between erythrocytes, thrombocytes and lymphocytes, no differences between T lymphocytes and B lymphocytes were seen.     

Brief communication: Minimally invasive bone sampling method for DNA analysis

Obtaining a bone sample for DNA analysis has traditionally been a destructive practice, which has resulted in reluctance on behalf of curators for skeletal collections to allow invasive testing. A novel minimally invasive bone sampling method for DNA analysis is presented here. This method uses a conventional hand drill wherein the bone sample is extracted from the intercondylar fossa of the femur; it does not interfere with any known anthropometric landmarks and only leaves a small hole on the surface of the bone. The temperature of the drill is documented and it was established due to the minor increase in temperature, that this should not affect the molecular integrity of the sample. This method is easily replicated and is suitable for both human and other animal skeletal material and can be applied to rare specimens with little risk. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Ecotourism for the survival of sea turtles and other wildlife

This paper discusses generally why humans should bother to conservesea turtles. In doing so, it considers both economic and non-economic reasonsand outlines threats to the existence of sea turtles and ways in which tourismmay either contribute to the conservation or decline of their populations.Turtle-based ecotourism at Mon Repos in southern Queensland is described. As aresult of a survey conducted by the authors, it is shown that turtle-basedecotourism at Mon Repos has positive social (indirect) consequences for theconservation of sea turtles. Furthermore, it is argued that ecotourismoperations at Mon Repos have positive direct impacts on the sustainability ofpopulations of sea turtles. However, using a simple model, it is emphasised thatthis impact is limited because turtles are migratory. A model is also developedto capture the possible relationship between turtle populations and thesustainability of ecotourism dependent on turtle populations, and is extended toother wildlife species. Significant interdependence exists between thesustainability of these two variables. The theory is related toCiriacy-Wantrup's social safe minimum conservation standard forspecies' survival.     

Characterization of cDNAs encoding p53 of Bombyx mori and Spodoptera frugiperda

Complementary DNAs encoding homologs of the tumor suppressor gene, p53, were characterized from two lepidopteran insects, Bombyx mori (Bm) and Spodoptera frugiperda (Sf). They encoded predicted proteins of 368 (41.2 kDa) (Bm) and 374 (42.5 kDa) (Sf) amino acids. The sequences shared 44% amino acid and 60% nucleotide sequence identity with each other, but exhibited less than 20% amino acid and 46% nucleotide sequence identity to Drosophila melanogaster p53. Despite the sequence diversity, conserved amino acids involved in DNA and zinc binding were present in the lepidopteran sequences. Expression of Sfp53-induced apoptosis in S. frugiperda cells, and antiserum made against recombinant Sfp53 recognized a protein whose abundance increased after treatment with DNA damaging agents.     

c-IAP1 is cleaved by caspases to produce a proapoptotic C-terminal fragment

Although human c-IAP1 and c-IAP2 have been reported to possess antiapoptotic activity against a variety of stimuli in several mammalian cell types, we observed that full-length c-IAP1 and c-IAP2 failed to protect cells from apoptosis induced by Bax overexpression, tumor necrosis factor alpha treatment or Sindbis virus infection. However, deletion of the C-terminal RING domains of c-IAP1 and c-IAP2 restored antiapoptotic activity, indicating that this region negatively regulates the antiapoptotic function of the N-terminal BIR domain. This finding is consistent with the observation by others that the spacer region and RING domain of c-IAP1 functions as an E3 ligase, promoting autoubiquitination and degradation of c-IAP1. In addition, we found that c-IAP1 is cleaved during apoptosis to 52- and 35-kDa fragments. Both fragments contain the C-terminal end of c-IAP1 including the RING finger. In vitro cleavage of c-IAP1 with apoptotic cell extracts or with purified recombinant caspase-3 produced similar fragments. Furthermore, transfection of cells with the spacer-RING domain alone suppressed the antiapoptotic function of the N-terminal BIR domain of c-IAP1 and induced apoptosis. Optimal death-inducing activity of the spacer-RING required both the spacer region and the zinc-binding RING domain of c-IAP1 but did not require the caspase recruitment domain located within the spacer region. To the contrary, deletion of the caspase recruitment domain increased proapoptotic activity, apparently by stabilizing the C-terminal fragment.