A Dynamic Protein Interaction Landscape of the Human Centrosome-Cilium Interface.

The centrosome is the primary microtubule organizing center of the cells and templates the formation of cilia, thereby operating at a nexus of critical cellular functions. Here, we use proximity-dependent biotinylation (BioID) to map the centrosome-cilium interface; with 58 bait proteins we generate a protein topology network comprising >7,000 interactions. Analysis of interaction profiles coupled with high resolution phenotypic profiling implicates a number of protein modules in centriole duplication, ciliogenesis, and centriolar satellite biogenesis and highlights extensive interplay between these processes. By monitoring dynamic changes in the centrosome-cilium protein interaction landscape during ciliogenesis, we also identify satellite proteins that support cilia formation. Systematic profiling of proximity interactions combined with functional analysis thus provides a rich resource for better understanding human centrosome and cilia biology. Similar strategies may be applied to other complex biological structures or pathways.

Interactome Rewiring Following Pharmacological Targeting of BET Bromodomains.

Targeting bromodomains (BRDs) of the bromo-and-extra-terminal (BET) family offers opportunities for therapeutic intervention in cancer and other diseases. Here, we profile the interactomes of BRD2, BRD3, BRD4, and BRDT following treatment with the pan-BET BRD inhibitor JQ1, revealing broad rewiring of the interaction landscape, with three distinct classes of behavior for the 603 unique interactors identified. A group of proteins associate in a JQ1-sensitive manner with BET BRDs through canonical and new binding modes, while two classes of extra-terminal (ET)-domain binding motifs mediate acetylation-independent interactions. Last, we identify an unexpected increase in several interactions following JQ1 treatment that define negative functions for BRD3 in the regulation of rRNA synthesis and potentially RNAPII-dependent gene expression that result in decreased cell proliferation. Together, our data highlight the contributions of BET protein modules to their interactomes allowing for a better understanding of pharmacological rewiring in response to JQ1.

Health facility assessment of small and sick newborn care in low- and middle-income countries: systematic tool development and operationalisation with NEST360 and UNICEF.

BACKGROUND: Each year an estimated 2.3 million newborns die in the first 28 days of life. Most of these deaths are preventable, and high-quality neonatal care is fundamental for surviving and thriving. Service readiness is used to assess the capacity of hospitals to provide care, but current health facility assessment (HFA) tools do not fully evaluate inpatient small and sick newborn care (SSNC). METHODS: Health systems ingredients for SSNC were identified from international guidelines, notably World Health Organization (WHO), and other standards for SSNC. Existing global and national service readiness tools were identified and mapped against this ingredients list. A novel HFA tool was co-designed according to a priori considerations determined by policymakers from four African governments, including that the HFA be completed in one day and assess readiness across the health system. The tool was reviewed by > 150 global experts, and refined and operationalised in 64 hospitals in Kenya, Malawi, Nigeria, and Tanzania between September 2019 and March 2021. RESULTS: Eight hundred and sixty-six key health systems ingredients for service readiness for inpatient SSNC were identified and mapped against four global and eight national tools measuring SSNC service readiness. Tools revealed major content gaps particularly for devices and consumables, care guidelines, and facility infrastructure, with a mean of 13.2% (n = 866, range 2.2-34.4%) of ingredients included. Two tools covered 32.7% and 34.4% (n = 866) of ingredients and were used as inputs for the new HFA tool, which included ten modules organised by adapted WHO health system building blocks, including: infrastructure, pharmacy and laboratory, medical devices and supplies, biomedical technician workshop, human resources, information systems, leadership and governance, family-centred care, and infection prevention and control. This HFA tool can be conducted at a hospital by seven assessors in one day and has been used in 64 hospitals in Kenya, Malawi, Nigeria, and Tanzania. CONCLUSION: This HFA tool is available open-access to adapt for use to comprehensively measure service readiness for level-2 SSNC, including respiratory support. The resulting facility-level data enable comparable tracking for Every Newborn Action Plan coverage target four within and between countries, identifying facility and national-level health systems gaps for action.

Quantifying health facility service readiness for small and sick newborn care: comparing standards-based and WHO level-2 + scoring for 64 hospitals implementing with NEST360 in Kenya, Malawi, Nigeria, and Tanzania.

BACKGROUND: Service readiness tools are important for assessing hospital capacity to provide quality small and sick newborn care (SSNC). Lack of summary scoring approaches for SSNC service readiness means we are unable to track national targets such as the Every Newborn Action Plan targets. METHODS: A health facility assessment (HFA) tool was co-designed by Newborn Essential Solutions and Technologies (NEST360) and UNICEF with four African governments. Data were collected in 68 NEST360-implementing neonatal units in Kenya, Malawi, Nigeria, and Tanzania (September 2019-March 2021). Two summary scoring approaches were developed: a) standards-based, including items for SSNC service readiness by health system building block (HSBB), and scored on availability and functionality, and b) level-2 + , scoring items on readiness to provide WHO level-2 + clinical interventions. For each scoring approach, scores were aggregated and summarised as a percentage and equally weighted to obtain an overall score by hospital, HSBB, and clinical intervention. RESULTS: Of 1508 HFA items, 1043 (69%) were included in standards-based and 309 (20%) in level-2 + scoring. Sixty-eight neonatal units across four countries had median standards-based scores of 51% [IQR 48-57%] at baseline, with variation by country: 62% [IQR 59-66%] in Kenya, 49% [IQR 46-51%] in Malawi, 50% [IQR 42-58%] in Nigeria, and 55% [IQR 53-62%] in Tanzania. The lowest scoring was family-centred care [27%, IQR 18-40%] with governance highest scoring [76%, IQR 71-82%]. For level-2 + scores, the overall median score was 41% [IQR 35-51%] with variation by country: 50% [IQR 44-53%] in Kenya, 41% [IQR 35-50%] in Malawi, 33% [IQR 27-37%] in Nigeria, and 41% [IQR 32-52%] in Tanzania. Readiness to provide antibiotics by culture report was the highest-scoring intervention [58%, IQR 50-75%] and neonatal encephalopathy management was the lowest-scoring [21%, IQR 8-42%]. In both methods, overall scores were low (< 50%) for 27 neonatal units in standards-based scoring and 48 neonatal units in level-2 + scoring. No neonatal unit achieved high scores of > 75%. DISCUSSION: Two scoring approaches reveal gaps in SSNC readiness with no neonatal units achieving high scores (> 75%). Government-led quality improvement teams can use these summary scores to identify areas for health systems change. Future analyses could determine which items are most directly linked with quality SSNC and newborn outcomes.

Spatial and proteomic profiling reveals centrosome-independent features of centriolar satellites.

Centriolar satellites are small electron-dense granules that cluster in the vicinity of centrosomes. Satellites have been implicated in multiple critical cellular functions including centriole duplication, centrosome maturation, and ciliogenesis, but their precise composition and assembly properties have remained poorly explored. Here, we perform in vivo proximity-dependent biotin identification (BioID) on 22 human satellite proteins, to identify 2,113 high-confidence interactions among 660 unique polypeptides. Mining this network, we validate six additional satellite components. Analysis of the satellite interactome, combined with subdiffraction imaging, reveals the existence of multiple unique microscopically resolvable satellite populations that display distinct protein interaction profiles. We further show that loss of satellites in PCM1-depleted cells results in a dramatic change in the satellite interaction landscape. Finally, we demonstrate that satellite composition is largely unaffected by centriole depletion or disruption of microtubules, indicating that satellite assembly is centrosome-independent. Together, our work offers the first systematic spatial and proteomic profiling of human centriolar satellites and paves the way for future studies aimed at better understanding the biogenesis and function(s) of these enigmatic structures.

Transcription coupled DNA repair protein UVSSA binds to DNA and RNA: Mapping of nucleic acid interaction sites on human UVSSA.

Transcription-coupled repair (TCR) is a dedicated pathway for the preferential repair of bulky transcription-blocking DNA lesions. These lesions stall the elongating RNA-polymerase II (RNAPII) triggering the recruitment of TCR proteins at the damaged site. UV-stimulated scaffold protein A (UVSSA) is a recently identified cofactor which is involved in stabilization of the TCR complex, recruitment of DNA-repair machinery and removal/restoration of RNAPII from the lesion site. Mutations in UVSSA render the cells TCR-deficient and have been linked to UV-sensitive syndrome. Human UVSSA is a 709-residue long protein with two short conserved domains; an N-terminal (residues 1-150) and a C-terminal (residues 495-605) domain, while the rest of the protein is predicted to be intrinsically disordered. The protein is well conserved in eukaryotes, however; none of its homologs have been characterized yet. Here, we have purified the recombinant human UVSSA and have characterized it using bioinformatics, biophysical and biochemical techniques. Using EMSA, SPR and fluorescence-based methods, we have shown that human UVSSA interacts with DNA and RNA. Furthermore, we have mapped the nucleic acid binding regions using several recombinant protein fragments containing either the N-terminal or the C-terminal domains. Our data indicate that UVSSA possesses at least two nucleic acid binding regions; the N-terminal domain and a C-terminal tail region (residues 606-662). These regions, far apart in sequence space, are predicted to be in close proximity in structure-space suggesting a coherent interaction with target DNA/RNA. The study may provide functional clues about the novel family of UVSSA proteins.

Implementation of distance learning IMCI training in rural districts of Tanzania.

BACKGROUND: The standard face-to-face training for the integrated management of childhood illness (IMCI) continues to be plagued by concerns of low coverage of trainees, the prolonged absence of trainees from the health facility to attend training and the high cost of training. Consequently, the distance learning IMCI training model is increasingly being promoted to address some of these challenges in resource-limited settings. This paper examines participants' accounts of the paper-based IMCI distance learning training programme in three district councils in Mbeya region, Tanzania. METHODS: A cross-sectional qualitative descriptive design was employed as part of an endline evaluation study of the management of possible serious bacterial infection in Busokelo, Kyela and Mbarali district councils of Mbeya Region in Tanzania. Key informant interviews were conducted with purposefully selected policymakers, partners, programme managers and healthcare workers, including beneficiaries and training facilitators. RESULTS: About 60 key informant interviews were conducted, of which 53% of participants were healthcare workers, including nurses, clinicians and pharmacists, and 22% were healthcare administrators, including district medical officers, reproductive and child health coordinators and programme officers. The findings indicate that the distance learning IMCI training model (DIMCI) was designed to address concerns about the standard IMCI model by enhancing efficiency, increasing outputs and reducing training costs. DIMCI included a mix of brief face-to-face orientation sessions, several weeks of self-directed learning, group discussions and brief face-to-face review sessions with facilitators. The DIMCI course covered topics related to management of sick newborns, referral decisions and reporting with nurses and clinicians as the main beneficiaries of the training. The problems with DIMCI included technological challenges related to limited access to proper learning technology (e.g., computers) and unfriendly learning materials. Personal challenges included work-study-family demands, and design and coordination challenges, including low financial incentives, which contributed to participants defaulting, and limited mentorship and follow-up due to limited funding and transport. CONCLUSION: DIMCI was implemented successfully in rural Tanzania. It facilitated the training of many healthcare workers at low cost and resulted in improved knowledge, competence and confidence among healthcare workers in managing sick newborns. However, technological, personal, and design and coordination challenges continue to face learners in rural areas; these will need to be addressed to maximize the success of DIMCI.

A Proteomic Survey of the Cystic Fibrosis Transmembrane Conductance Regulator Surfaceome.

The aim of this review article is to collate recent contributions of proteomic studies to cystic fibrosis transmembrane conductance regulator (CFTR) biology. We summarize advances from these studies and create an accessible resource for future CFTR proteomic efforts. We focus our attention on the CFTR interaction network at the cell surface, thus generating a CFTR 'surfaceome'. We review the main findings about CFTR interactions and highlight several functional categories amongst these that could lead to the discovery of potential biomarkers and drug targets for CF.

Proximity Profiling of the CFTR Interaction Landscape in Response to Orkambi.

Deletion of phenylalanine 508 (∆F508) of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) anion channel protein is the leading cause of Cystic Fibrosis (CF). Here, we report the analysis of CFTR and ∆F508-CFTR interactomes using BioID (proximity-dependent biotin identification), a technique that can also detect transient associations. We identified 474 high-confidence CFTR proximity-interactors, 57 of which have been previously validated, with the remainder representing novel interaction space. The ∆F508 interactome, comprising 626 proximity-interactors was markedly different from its wild type counterpart, with numerous alterations in protein associations categorized in membrane trafficking and cellular stress functions. Furthermore, analysis of the ∆F508 interactome in cells treated with Orkambi identified several interactions that were altered as a result of this drug therapy. We examined two candidate CFTR proximity interactors, VAPB and NOS1AP, in functional assays designed to assess surface delivery and overall chloride efflux. VAPB depletion impacted both CFTR surface delivery and chloride efflux, whereas NOS1AP depletion only affected the latter. The wild type and ∆F508-CFTR interactomes represent rich datasets that could be further mined to reveal additional candidates for the functional rescue of ∆F508-CFTR.

Target highlights in CASP14: Analysis of models by structure providers.

The biological and functional significance of selected Critical Assessment of Techniques for Protein Structure Prediction 14 (CASP14) targets are described by the authors of the structures. The authors highlight the most relevant features of the target proteins and discuss how well these features were reproduced in the respective submitted predictions. The overall ability to predict three-dimensional structures of proteins has improved remarkably in CASP14, and many difficult targets were modeled with impressive accuracy. For the first time in the history of CASP, the experimentalists not only highlighted that computational models can accurately reproduce the most critical structural features observed in their targets, but also envisaged that models could serve as a guidance for further studies of biologically-relevant properties of proteins.

Expression of a heptelidic acid-insensitive recombinant GAPDH from Trichoderma virens, and its biochemical and biophysical characterization.

Trichoderma virens genome harbors two isoforms of GAPDH, one (gGPD) involved in glycolysis and the other one (vGPD) in secondary metabolism. vGPD is expressed as part of the "vir" cluster responsible for the biosynthesis of volatile sesquiterpenes. The secondary metabolism-associated GAPDH is tolerant to the anti-cancer metabolite heptelidic acid (HA), produced by T. virens. Characterizing the HA-tolerant form of GAPDH, thus has implications in cancer therapy. In order to get insight into the mechanism of HA-tolerance of vGPD, we have purified recombinant form of this protein. The protein displays biochemical and biophysical characteristics analogous to the gGPD isoform. It exists as a tetramer with Tm of about 56.5 °C, and displays phosphorylation enzyme activity with Km and Kcat of 0.38 mM and 2.55 sec-1, respectively. The protein weakly binds to the sequence upstream of the vir4 gene that codes for the core enzyme (a terpene cyclase) of the "vir" cluster. The EMSA analysis indicates that vGPD may not act as a transcription factor driving the "vir" cluster, at least not by directly binding to the promoter region. We also succeeded in obtaining small crystals of this protein. We have constructed structural models of vGPD and gGPD of T. virens. In silico constrained docking analysis reveals weaker binding of heptelidic acid in vGPD, compared to gGPD protein.

Mosquito-larvicidal BinA toxin displays affinity for glycoconjugates: Proposal for BinA mediated cytotoxicity.

Lysinibacillus sphaericus parasporal BinAB toxin displays mosquito larvicidal activity against Culex and Anopheles, but several Aedes species are refractory. Recently reported crystal structure of BinAB revealed the presence of N-terminal lectin-like domain in BinA. Hemagglutination and hemolytic activities were not observed for BinA in the present studies. We attempted to characterize carbohydrate specificity of BinA by high-throughput approaches using extrinsic fluorescence and thermofluor shift assay. A total of 34 saccharides (mono-, di- and polysaccharides, and glycoproteins) were used for initial high-throughput screening. The promising glycans were identified based on significant change in the fluorescence intensity. Surface plasmon resonance revealed differential binding of BinA with glycoproteins (fetuin, asialofetuin and thyroglobulin) and affinity for simple sugars, l-fucose and l-arabinose. In the limited carbohydrate competition assay, arabinose, fucose and fetuin inhibited BinA toxicity towards Culex larvae. This study for the first time provides direct evidence that BinA is competent to bind diverse and structurally different glycosylated proteins. This activity may be linked to its intracellular cytotoxicity, as protein N-glycosylation is thought to be critical for development and survival of insect larvae. The glycoproteins do not form stable complexes with BinA, however, as observed in the pull-down assay using affinity immobilized BinA and in native-PAGE analysis. As BinA displays only mild affinity with receptor polypeptide, we hypothesize that toxin-receptor specificity of BinA in Culex may be mediated by dual interaction of BinA with glycan core of GPI anchor and receptor polypeptide. The study shall be useful for refining strategies for improving larvicidal activity and for broadening target specificity of BinAB toxin.

PEGylation Enhances Mosquito-Larvicidal Activity of Lysinibacillus sphaericus Binary Toxin.

Toxic strains of Lysinibacillus sphaericus have been used in the field for larval control of mosquito vector diseases. The high toxicity of L. sphaericus is attributed to the binary (BinAB) toxin produced as parasporal crystalline inclusions during the early stages of sporulation. BinA and BinB, the primary components of these spore-crystals, exert high toxicity when administered together. However, instability, short half-lives, and rapid proteolytic digestion can limit their use as an effective insecticide. BinA alone displays larvicidal toxicity, in the absence of BinB, albeit with much reduced activity. Here for the first time, we demonstrate the beneficial effect of PEGylation (covalent attachment of polyethylene glycol) on mosquito-larvicidal activity of BinA. Polymer conjugation was achieved using 750 Da polyethylene glycol (PEG) at two different pH values (pH 7.2 and 8.5). Two different isoforms of the biopolymers, purified to homogeneity, were highly water-soluble and resistant to trypsin and proteinase K. The mono-PEGylated BinA isoforms also displayed preservation of the toxin structure with improved thermal stability by about 3-5 °C, as evident from thermal denaturation studies by circular dichroism and differential scanning fluorimetry. Notably, PEGylation enhanced BinA toxicity by nearly 6-fold. The PEGylated BinA isoforms alone displayed high larvicidal activity (LC50 value of ∼3.4 ng/mL) against the third instar Culex larvae, which compares favorably against LC50 reported for the combination of BinA and BinB proteins. Since BinA can be synthesized easily through recombinant technology and easily PEGylated, the conjugated biopolymers offer a promising opportunity for mosquito control programs.

Myotubularin-related proteins 3 and 4 interact with polo-like kinase 1 and centrosomal protein of 55 kDa to ensure proper abscission.

The myotubularins are a family of phosphatases that dephosphorylate the phosphatidylinositols phosphatidylinositol-3-phosphate and phosphatidylinositol-3,5-phosphate. Several family members are mutated in disease, yet the biological functions of the majority of myotubularins remain unknown. To gain insight into the roles of the individual enzymes, we have used affinity purification coupled to mass spectrometry to identify protein-protein interactions for the myotubularins. The myotubularin interactome comprises 66 high confidence (false discovery rate ≤1%) interactions, including 18 pairwise interactions between individual myotubularins. The results reveal a number of potential signaling contexts for this family of enzymes, including an intriguing, novel role for myotubularin-related protein 3 and myotubularin-related protein 4 in the regulation of abscission, the final step of mitosis in which the membrane bridge remaining between two daughter cells is cleaved. Both depletion and overexpression of either myotubularin-related protein 3 or myotubularin-related protein 4 result in abnormal midbody morphology and cytokinesis failure. Interestingly, myotubularin-related protein 3 and myotubularin-related protein 4 do not exert their effects through lipid regulation at the midbody, but regulate abscission during early mitosis, by interacting with the mitotic kinase polo-like kinase 1, and with centrosomal protein of 55 kDa (CEP55), an important regulator of abscission. Structure-function analysis reveals that, consistent with known intramyotubularin interactions, myotubularin-related protein 3 and myotubularin-related protein 4 interact through their respective coiled coil domains. The interaction between myotubularin-related protein 3 and polo-like kinase 1 relies on the divergent, nonlipid binding Fab1, YOTB, Vac1, and EEA1 domain of myotubularin-related protein 3, and myotubularin-related protein 4 interacts with CEP55 through a short GPPXXXY motif, analogous to endosomal sorting complex required for transport-I components. Disruption of any of these interactions results in abscission failure, by disrupting the proper recruitment of CEP55, and subsequently, of endosomal sorting complex required for transport-I, to the midbody. Our data suggest that myotubularin-related protein 3 and myotubularin-related protein 4 may act as a bridge between CEP55 and polo-like kinase 1, ensuring proper CEP55 phosphorylation and regulating CEP55 recruitment to the midbody. This work provides a novel role for myotubularin-related protein 3/4 heterodimers, and highlights the temporal and spatial complexity of the regulation of cytokinesis.

Crystal structure analysis of C-phycoerythrin from marine cyanobacterium Phormidium sp. A09DM.

The role of unique sequence features of C-phycoerythrin, isolated from Phormidium sp. A09DM, has been investigated by crystallographic studies. Two conserved indels (i.e. inserts or deletions) are found in the ß-subunit of Phormidium phycoerythrin that are distinctive characteristics of large number of cyanobacterial sequences. The identified signatures are a two-residue deletion from position 21 and a nine-residue insertion at position 146. Crystals of Phormidium phycoerythrin were obtained at pH values of 5 and 8.5, and structures have been resolved to high precision at 1.95 and 2.1 Å resolution, respectively. In both the structures, heterodimers of α- and ß- subunits assemble as hexamers. The 7-residue insertion at position 146 significantly reduces solvent exposure of π-conjugated A-C rings of a phycoerythrobilin (PEB) chromophore, and can influence energy absorption and energy transfer characteristics. The structural analyses (with 12-fold redundancy) suggest that protein micro-environment alone dictates the conformation of bound chromophores. The low- and high-energy absorbing chromophores are identified based on A-B ring coplanarity. The spatial distribution of these is found to be similar to that observed in R-phycoerythrin, suggesting the direction of energy transfer from outer-surface of hexamer to inner-hollow cavity in the Phormidium protein. The crystal structures also reveal that a commonly observed Hydrogen-bonding network in phycobiliproteins, involving chromophore bound to α-subunit and amino acid at position 73 of ß-subunit, may not be essential for structural and functional integrity of C-phycoerythrin orthologs. In solution, the protein displays slight red shift and decrease in fluorescence emission at acidic pH. The mechanism for which may be static and correlates with the proximity of +ve electric field of Arg148 to the C-ring of a PEB chromophore.

Inpatient care of small and sick newborns: a multi-country analysis of health system bottlenecks and potential solutions.

BACKGROUND: Preterm birth is the leading cause of child death worldwide. Small and sick newborns require timely, high-quality inpatient care to survive. This includes provision of warmth, feeding support, safe oxygen therapy and effective phototherapy with prevention and treatment of infections. Inpatient care for newborns requires dedicated ward space, staffed by health workers with specialist training and skills. Many of the estimated 2.8 million newborns that die every year do not have access to such specialised care. METHODS: The bottleneck analysis tool was applied in 12 countries in Africa and Asia as part of the Every Newborn Action Plan process. Country workshops involved technical experts to complete the survey tool, which is designed to synthesise and grade health system "bottlenecks" (or factors that hinder the scale up) of maternal-newborn intervention packages. For this paper, we used quantitative and qualitative methods to analyse the bottleneck data, and combined these with literature review, to present priority bottlenecks and actions relevant to different health system building blocks for inpatient care of small and sick newborns. RESULTS: Inpatient care of small and sick newborns is an intervention package highlighted by all country workshop participants as having critical health system challenges. Health system building blocks with the highest graded (significant or major) bottlenecks were health workforce (10 out of 12 countries) and health financing (10 out of 12 countries), followed by community ownership and partnership (9 out of 12 countries). Priority actions based on solution themes for these bottlenecks are discussed. CONCLUSIONS: Whilst major bottlenecks to the scale-up of quality inpatient newborn care are present, effective solutions exist. For all countries included, there is a critical need for a neonatal nursing cadre. Small and sick newborns require increased, sustained funding with specific insurance schemes to cover inpatient care and avoid catastrophic out-of-pocket payments. Core competencies, by level of care, should be defined for monitoring of newborn inpatient care, as with emergency obstetric care. Rather than fatalism that small and sick newborns will die, community interventions need to create demand for accessible, high-quality, family-centred inpatient care, including kangaroo mother care, so that every newborn can survive and thrive.

Characterization of a plant (rice) translin and its comparative analysis with human translin.

MAIN CONCLUSION: For the first time, a plant (rice) translin was characterized. The rice translin protein, which was octameric in native state, bound efficiently to single-stranded DNA and RNA. Translin, a DNA-/RNA-binding protein, is expressed in brain, testis and in certain malignancies. It is involved in chromosomal translocation, mRNA metabolism, transcriptional regulation and telomere protection. Studies from human, mice, drosophila and yeast have revealed that it forms an octameric ring, which is important for its function. In spite of the absence of neuronal functions and cancer processes, translin is present in plant systems, but information on plant translin is lacking. Here we report the characterization of a plant (rice) translin. Translin cDNA from O. sativa was cloned into an expression vector; protein was over-expressed in E. coli and subsequently purified to homogeneity. Circular dichroism and homology-based modeling showed that the rice translin protein was similar to the other translin proteins. Native PAGE and gel-filtration analyses showed rice translin to form an octamer and this octameric assembly was independent of disulphide bonds. Rice translin bound to single-stranded DNA sequences like human translin, but not to the double-stranded DNA. Rice translin bound more efficiently to linear DNA (with staggered ends) than open or closed circular DNA. Rice translin also bound to RNA, like its human counterpart. Rice translin displays all the characteristic properties of the translin group of proteins and does indeed qualify as a bonafide "translin" protein. To our knowledge, this is the first report wherein the translin protein from a plant source has been functionally characterized. Understanding the translin biology from plant systems will give the new insights into its functional role during plant development.

Sarcomatous transformation of osteochondroma of the coronoid process forming pseudoarthrosis with zygomatic arch mistaken for Jacob disease.

Osteochondromas are the most common benign osseous neoplasms, with a propensity to involve long bones. The involvement of the coronoid process is extremely rare, and osteochondromas of the coronoid process may form pseudoarticulations with the zygomatic arch when large, an entity that is extremely rare and termed as Jacob disease. Sarcomatous degeneration of osteochondroma of the coronoid process is an extremely rare entity and has not been described to date. Only 1 case of primary mesenchymal chondrosarcoma has been described. We present a case of a 24-year-old man with a chondrosarcoma of the coronoid process, who was wrongly diagnosed with Jacob disease on the basis of radiologic findings.

Sonographic diagnosis of primary hydatid disease in the breast: the scroll sign.

Primary hydatid disease of breast is a rare entity and is caused by the larval stage of Echinococcus granulosus. The disease is more commonly seen in sheep-rearing populations and imaging plays a pivotal role in its diagnosis. Several imaging signs have been described in relation to hydatid cysts. However, the "scroll sign," due to the infolding of the endocyst, has rarely been encountered, with only one similar case in literature, in which the imaging findings were inconclusive. We present a case of primary hydatid disease of breast in a young Asian woman, with the sonographic scroll sign.