Response of the cytoplasmic and membrane proteome of Corynebacterium glutamicum ATCC 13032 to pH changes

<p>Abstract</p> <p>Background</p> <p><it>C. glutamicum </it>has traditionally been grown in neutral-pH media for amino acid production, but in a previous article we reported that this microorganism is a moderate alkaliphile since it grows optimally at pH 7.0–9.0, as shown in fermentor studies under tightly controlled pH conditions. We determined the best pH values to study differential expression of several genes after acidic or basic pH conditions (pH 6.0 for acidic expression and pH 9.0 for alkaline expression). Thus, it was interesting to perform a detailed analysis of the pH-adaptation response of the proteome of <it>C. glutamicum </it>ATCC 13032 to clarify the circuits involved in stress responses in this bacterium. In this paper we used the above indicated pH conditions, based on transcriptional studies, to confirm that pH adaptation results in significant changes in cytoplasmatic and membrane proteins.</p> <p>Results</p> <p>The cytoplasmatic and membrane proteome of <it>Corynebacterium glutamicum </it>ATCC 13032 at different pH conditions (6.0, 7.0 and 9.0) was analyzed by classical 2D-electrophoresis, and by anion exchange chromatography followed by SDS-PAGE (AIEC/SDS-PAGE). A few cytoplasmatic proteins showed differential expression at the three pH values with the classical 2D-technique including a hypothetical protein <it>cg</it>2797, L-2.3-butanediol dehydrogenase (ButA), and catalase (KatA). The AIEC/SDS-PAGE technique revealed several membrane proteins that respond to pH changes, including the succinate dehydrogenase complex (SdhABCD), F₀F₁-ATP synthase complex subunits b, α and δ (AtpF, AtpH and AtpA), the nitrate reductase II α subunit (NarG), and a hypothetical secreted/membrane protein <it>cg</it>0752. Induction of the F₀F₁-ATP synthase complex β subunit (AtpD) at pH 9.0 was evidenced by Western analysis. By contrast, L-2.3-butanediol dehydrogenase (ButA), an ATPase with chaperone activity, the ATP-binding subunit (ClpC) of an ATP-dependent protease complex, a 7 TMHs hypothetical protein <it>cg</it>0896, a conserved hypothetical protein <it>cg</it>1556, and the dihydrolipoamide acyltransferase SucB, were clearly up-regulated at pH 6.0.</p> <p>Conclusion</p> <p>The observed protein changes explain the effect of the extracellular pH on the growth and physiology of <it>C. glutamicum</it>. Some of the proteins up-regulated at alkaline pH respond also to other stress factors suggesting that they serve to integrate the cell response to different stressing conditions.</p

Acquired periungual fibrokeratoma: surgery treatment

Acquired periungual fibrokeratoma is a benign fibroepitelial tumor, relatively common, but with minor incidence at the foot. It is characterized by presenting a fleshy mass covered with hyperpigmented skin and with hyperqueratosis in its distal portion, whose consistence is strong and "indurada" with a size that varies from 5 to 10 mm in length. Sometimes it can be painful after minor trauma or it can even bleed. In that case, surgical treatment can be suggested, as in the case reported. We present the case of a 31 years old patient, who comes to the office due to a painful isolated periungeal fibroma at the level of the third right toe, being recommended the surgical excision of the mass. Blood analysis and dorsolateral and dorsoplantar x-rays are required, to make sure that there´s no evidence of underlying bony pathology. The surgical technique has been carried out, under local anaesthesia making an elliptical incision following the lines of tension of the skin, and removing the fibroma. Sutures were necessary to heal the wound. After removing the mass, a biopsy was carried out and sent to the pathological anatomy department to ensure the diagnosis. The postoperative period was painless and the appearance of the toe was excellent. After one year follow-up, nor recurrences or associated problems appeared. We conclude that acquired periungual fibrokeratoma represents a well defined clinically and histologically benign tumor, easily diagnosed. The surgical approach appears to be as the best way to manage the situation definitively.Acquired periungual fibrokeratoma is a benign fibroepitelial tumor, relatively common, but with minor incidence at the foot. It is characterized by presenting a fleshy mass covered with hyperpigmented skin and with hyperqueratosis in its distal portion, whose consistence is strong and "indurada" with a size that varies from 5 to 10 mm in length. Sometimes it can be painful after minor trauma or it can even bleed. In that case, surgical treatment can be suggested, as in the case reported. We present the case of a 31 years old patient, who comes to the office due to a painful isolated periungeal fibroma at the level of the third right toe, being recommended the surgical excision of the mass. Blood analysis and dorsolateral and dorsoplantar x-rays are required, to make sure that there´s no evidence of underlying bony pathology. The surgical technique has been carried out, under local anaesthesia making an elliptical incision following the lines of tension of the skin, and removing the fibroma. Sutures were necessary to heal the wound. After removing the mass, a biopsy was carried out and sent to the pathological anatomy department to ensure the diagnosis. The postoperative period was painless and the appearance of the toe was excellent. After one year follow-up, nor recurrences or associated problems appeared. We conclude that acquired periungual fibrokeratoma represents a well defined clinically and histologically benign tumor, easily diagnosed. The surgical approach appears to be as the best way to manage the situation definitively

Contribution of Genetic Background, Traditional Risk Factors, and HIV-Related Factors to Coronary Artery Disease Events in HIV-Positive Persons

We show in human immunodeficiency virus-positive persons that the coronary artery disease effect of an unfavorable genetic background is comparable to previous studies in the general population, and comparable in size to traditional risk factors and antiretroviral regimens known to increase cardiovascular ris