Catarrhine juvenile mortality in captivity,under seminatural conditions,and in the wild

Juvenile mortality is an important problem in the development of captive populations. I compiled data from published literature on abortion, premature mortality, stillbirth, and death of unweaned young. Cumulative mortality incidences (CMI) during the first month in captive populations (CP) of Cercopithecoidea range between 13 and 51%, and CMI in the first year between 28 and 56%. Mortality rate during the first year ranges between <4 and 48% in free- ranging populations (FRP) and between 10 and 60% in wild populations (WP). Much of the juvenile mortality in CP appears to occur in the first month, whereas in FRP and WP mortality is more scattered throughout the juvenile period. High mortality rates occur in both CP and WP of nonhuman Hominoidea. Mortality rate during the first month in CP is between 12 and 36% for the Hylobatidae and between 18 and 31% for the Pongidae. If the entire juvenile period is considered, gorilla CP and WP have comparable CMI, while CMI is higher in WP than CP for chimpanzees. Most of the juvenile mortality in CP of chimpanzees occurs before the age of 1 year. Trauma, including infanticide and maternal inadequacy, seems to be a more important factor in infant mortality of Cercopithecoidea than infectious disease is. Relatively frequent reports of congenital, hereditary, and/or genetically determined malformations in the Cercopithecoidea may be related to the long use of animals in this group for laboratory purposes. Infectious disease is the most important cause of nonhuman hominoid juvenile mortality, followed by trauma and maternal disorders, particularly related aberrant maternal behavior. Cercopithecoid juvenile mortality risk factors most frequently mentioned in the literature are sex of the infant and rank of the mother: dominant females produce more female offspring, and juvenile males suffer higher mortality than females do. The female skewed sex ratio at birth in gorillas and chimpanzees could be explained by the local resource competition theory. Higher male mortality rates occur in nonhuman Hominoidea, except in two Hylobatesspp. and Pan paniscus,which have higher female mortality. Parity and rearing history of the mother are very important risk factors in nonhuman hominoid infant mortality.     

High-level expression of active HIV-1 integrase from a synthetic gene in human cells.

A synthetic gene encoding for HIV-1 integrase was designed to circumvent the intrinsic instability and the repressor elements present in the wild-type gene. High-level expression of HIV-1 integrase was obtained in various human cell lines independently of viral accessory proteins. A human 293T cell line was selected that stably expresses HIV-1 integrase and has growth kinetics comparable to the parental cell line. The enzyme was localized in the nucleus and remained stably associated with the chromosomes during mitosis. Lentiviral vector particles carrying the inactivating D64V mutation in the integrase gene were capable of stably transducing 293T cells when complemented in the producer cells with integrase expressed from the synthetic gene. When the cell line that stably expresses integrase was infected with the defective viral particles, complementation of integrase activity was detected as well. Expression of active HIV-1 integrase in human cells will facilitate the study of the interplay between host and viral factors during integration.     

Interaction of the HIV-1 Intasome with Transportin 3 Protein (TNPO3 or TRN-SR2)

Transportin 3 (TNPO3 or TRN-SR2) has been shown to be an important cellular factor for early steps of lentiviral replication. However, separate studies have implicated distinct mechanisms for TNPO3 either through its interaction with HIV-1 integrase or capsid. Here we have carried out a detailed biophysical characterization of TNPO3 and investigated its interactions with viral proteins. Biophysical analyses including circular dichroism, analytical ultracentrifugation, small-angle x-ray scattering, and homology modeling provide insight into TNPO3 architecture and indicate that it is highly structured and exists in a monomer-dimer equilibrium in solution. In vitro biochemical binding assays argued against meaningful direct interaction between TNPO3 and the capsid cores. Instead, TNPO3 effectively bound to the functional intasome but not to naked viral DNA, suggesting that TNPO3 can directly engage the HIV-1 IN tetramer prebound to the cognate DNA. Mass spectrometry-based protein footprinting and site-directed mutagenesis studies have enabled us to map several interacting amino acids in the HIV-1 IN C-terminal domain and the cargo binding domain of TNPO3. Our findings provide important information for future genetic analysis to better understand the role of TNPO3 and its interacting partners for HIV-1 replication.     

A proteome map of the pituitary melanotrope cell activated by black‐background adaptation of Xenopus laevis

Upon transfer of Xenopus laevis from a white to a black background, the melanotrope cells in the pituitary pars intermedia secrete α‐melanocyte‐stimulating hormone, which stimulates dispersion of melanin pigment in skin melanophores. This adaptive behavior is under the control of neurotransmitters and neuropeptides of hypothalamic origin. The α‐melanocyte‐stimulating hormone‐producing cells and their hypothalamic control system provide an interesting model to study proteins required for biosynthetic and secretory processes involved in peptide hormone production and for brain–pituitary signaling. We present a 2‐D PAGE‐based proteome map of melanotrope cells from black‐adapted animals, identifying 204 different proteins by MS analysis.     

Discovery of small molecule HIV-1 integrase dimerization inhibitors

Human immunodeficiency virus-1 integrase (HIV-1 IN) inserts the viral DNA into host cell chromatin in a multistep process. This enzyme exists in equilibrium between monomeric, dimeric, tetrameric and high order oligomeric states. However, monomers of IN are not capable of supporting its catalytic functions and the active form has been shown to be at least a dimer. As a consequence, the development of inhibitors targeting IN dimerization constitutes a promising novel antiviral strategy. In this work, we successfully combined different computational techniques in order to identify small molecule inhibitors of IN dimerization. Additionally, a novel AlphaScreen-based IN dimerization assay was used to evaluate the inhibitory activities of the selected compounds. To the best of our knowledge, this study represents the first successful virtual screening and evaluation of small molecule HIV-1 IN dimerization inhibitors, which may serve as attractive hit compounds for the development of novel anti-HIV.     

Immunohistochemical detection of transgene expression in the brain using small epitope tags

Background  

In vivo overexpression of proteins is a powerful approach to study their biological function, generate disease models or evaluate gene therapy approaches. In order to investigate an exogenously expressed protein, specific and sensitive detection is essential. Unfortunately, antibodies that allow histological detection of the protein of interest are not always readily available. The use of an epitope tag fused to the protein can circumvent this problem as well as provide the possibility to discriminate endogenous from overexpressed proteins. In order to minimize impact on the bioactivity and biodistribution of the overexpressed protein, preference is given to small tags.