Mapping of the interaction site of CP12 with glyceraldehyde-3-phosphate dehydrogenase from Chlamydomonas reinhardtii

The 8.5 kDa chloroplast protein CP12 is essential for assembly of the phosphoribulokinase ⁄ glyceraldehyde-3-phosphate dehydrogenase (GAPDH) complex from Chlamydomonas reinhardtii. After reduction of this complex with thioredoxin, phosphoribulokinase is released but CP12 remains tightly associated with GAPDH and downregulates its NADPH-dependent activity. We show that only incubation with reduced thioredoxin and the GAPDH substrate 1,3-bisphosphoglycerate leads to dissociation of the GAPDH⁄ CP12 complex. Consequently, a significant twofold increase in the NADPHdependent activity of GAPDH was observed. 1,3-Bisphosphoglycerate or reduced thioredoxin alone weaken the association, causing a smaller increase in GAPDH activity. CP12 thus behaves as a negative regulator of GAPDH activity. A mutant lacking the C-terminal disulfide bridge is unable to interact with GAPDH, whereas absence of the N-terminal disulfide bridge does not prevent the association with GAPDH. Trypsin-protection experiments indicated that GAPDH may be also bound to the central a-helix of CP12 which includes residues at position 36 (D) and 39 (E). Mutants of CP12 (D36A, E39A and E39K) but not D36K, reconstituted the GAPDH⁄ CP12 complex. Although the dissociation constants measured by surface plasmon resonance were 2.5–75-fold higher with these mutants than with wild-type CP12 and GAPDH, they remained low. For the D36K mutation, we calculated a 7 kcalÆmol)1 destabilizing effect, which may correspond to loss of the stabilizing effect of an ionic bond for the interaction between GAPDH and CP12. It thus suggests that electrostatic forces are responsible for the interaction between GAPDH and CP12

Primary Cutaneous B-Cell Lymphoma Co-Existing with Mycosis Fungoides—A Case Report and Overview of the Literature

The existence of two sequential lymphomas, one localized and one systemic, either both with B or T lymphocytes, or one with B cells and one with T cells, with the same patient, is a known possibility. The second lymphoma is often induced by immunodepression or by the initial treatment. However, the existence of two cutaneous lymphomas with different cell lines, without systemic involvement, represents an uncommon situation. In this report, we describe the case of a 37-year-old man with an initial diagnosis of PMZBCL that over 10 months also developed a MF patch/plaque on the left leg

Mass spectrometric analysis of the interactions between CP12, a chloroplast protein, and metal ions: a possible regulatory role within a PRK/GAPDH/CP12 complex

The small chloroplast protein CP12 plays the role of a protein linker in the assembly process of a PRK/GAPDH/CP12 complex that is involved in CO2 assimilation in photosynthetic organisms. The redox state of CP12 regulates its role as a protein linker. Only the oxidized protein, with two disulfide bonds, is active in complex formation. Several observations indicating that CP12 might bind a metal ion led us to screen the binding of different metal ions on oxidized or reduced CP12 using non-covalent electrospray ionization mass spectrometry (ESI-MS) experiments. The oxidized protein bound specifically Cu2+ and Ni2+ (Kd of 26+/-1 microM and 11+/-1 microM, respectively); other cations such as Fe2+ and Zn2+ did not bind, while cations such as Cd2+ formed non-specific adducts to CP12. Similar results were obtained for metal ions on screening with the reduced CP12. Interestingly, the present results suggest that Cu2+ catalyzes the re-formation of the disulfide bonds of the reduced CP12, leading to recovery of the fully oxidized CP12 that is then able to bind a Cu2+ ion. Finally the high similarity between CP12 and copper chaperones from Arabidopsis thaliana, as judged by hydrophobic cluster analysis, provides additional evidence for the relevance of metal binding for the in vivo situation. The findings that CP12 is able to bind a metal ion, and that Cu2+ catalyzes the oxidation of the thiol groups of CP12, are new characteristics of this protein that may prove to be important in the regulation of the assembly process of the PRK/GAPDH/CP12 complex. Arnaud Delobel, Emmanuelle Graciet, Simona Andreescu, Brigitte Gontero, Frederic Halgand and Olivier Laprevot

The Role of Circular RNA for Early Diagnosis and Improved Management of Patients with Cardiovascular Diseases

Cardiovascular diseases (CVDs) are responsible for approximately 17.9 million deaths every year. There is growing evidence that circular RNAs (circRNAs) may play a significant role in the early diagnosis and treatment of cardiovascular diseases. As regulatory molecules, circular RNAs regulate gene expression, interact with proteins and miRNAs, and are translated into proteins that play a key role in a wide variety of biological processes, including the division and proliferation of cells, as well as the growth and development of individuals. An overview of the properties, expression profiles, classification, and functions of circRNAs is presented here, along with an explanation of their implications in cardiovascular diseases including heart failure, hypertension, ischemia/reperfusion injury, myocardial infarction, cardiomyopathies, atherosclerosis, and arrhythmia

A rare case of partial trisomy 8q24.12-q24.3 and partial monosomy of 8q24.3: Prenatal diagnosis and clinical findings

Objective: We describe a rare case of “pure” 8q duplication diagnosed prenatally by conventional karyotyping, that was further characterized by array comparative genomic hybridization (aCGH). Case report: A 39-year-old, primigravida woman underwent amniocentesis at 23 weeks of gestation because of an abnormal second trimester maternal serum screening for Down syndrome. Conventional cytogenetic analysis demonstrated a karyotype of 46,XX,der(8) (q24.12q24.3) and aCGH identified a duplication of approximately 27 Mb, affecting the distal region of chromosome 8q24.12-q24.3. Parenteral karyotype of both parents was normal and excluded familial translocation or other rearrangements. Although prenatal ultrasound examination showed multiple anomalies the parents decided to keep the pregnancy. The baby was born at 38 weeks of gestation, with an Apgar score of 2. The evolution was unfavorable, and he died within the first 24 h of birth. Conclusion: Molecular investigations contribute to a more accurate characterization of the patients with these rare duplication, but also for estimating their prognosis. Keywords: Array comparative genomic hybridization, Chromosome 8 duplication, Prenatal diagnosi

Latent Tuberculosis in Psoriasis Patients on Biologic Therapies: Real-World Data from a Care Center in Romania

Background and Objectives: Psoriasis is a chronic and inflammatory condition that has a huge impact on the patient’s quality of life. Biological treatment improved psoriasis therapy, with impressive results seen in the evolution of the disease and the patient’s quality of life. However, the risk of mycobacterium tuberculosis (MTB) infection reactivation is well-known to biological therapy, which raises problems especially in an endemic country. Materials and Methods: In this study, we followed moderate to severe psoriasis patients who had latent tuberculosis infection (LTBI) following treatment with a biological therapy approved in Romania. Results: The patients were evaluated at baseline and then followed-up with Mantoux tests and chest X-rays every year, resulting in 54 patients being diagnosed with LTBI. At the initial evaluation, 30 patients with LTBI were identified, and 24 more were identified during biological therapy. These patients were given prophylactic treatment. Out of the 97 participants in this retrospective study, 25 required association of methotrexate (MTX) alongside biological therapy. We compared the prevalence of positive Mantoux tests in patients with combined therapy with that of patients only on biological treatment, and the results were higher in the combined therapy group. Conclusion: All the patients in the study were vaccinated against tuberculosis (TB) after birth, and none were diagnosed with active tuberculosis (aTB) before or after the start of therapy according to the pulmonologist