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Objective To analyze the albuminocytologic dissociation in cerebrospinal fluid （CSF） and differences in CSF protein levels in Guillain-Barré syndrome （GBS）patients with various types of antecedent infections and investigate the correlation between antecedent infections and increased CSF protein levels in GBS patients. Methods Clinical data and CSF analysis results of 198 GBS patients were collected. Enzyme-linked immunosorbent assay （ELISA） was employed to detect 14 types of infectious pathogens in the serum of GBS patients. The proportion of albuminocytologic dissociation and the differences in CSF protein levels were analyzed in GBS patients with different antecedent infections. Results In total，55.1% （109/198） of GBS patients had serological positivity for infectious pathogens，23.7% （47/198） for Campylobacter jejuni，20.7% （41/198） for Influenza A virus，15.2% （30/198） for Influenza B virus. Among them，18.7% （37/198） of GBS patients had serological positivity for two or more pathogens. In total，73.7% （146/198） of GBS patients had albuminocytologic dissociation in CSF. Among single pathogen-positive patients，83.3% （25/30） of Campylobacter jejuni positive patients showed albuminocytologic dissociation in CSF，100% （18/18） of Influenza A virus patients，6/7 of influenza B virus patients，4/5 of Hepatitis A virus patients，4/5 of Dengue virus patients，4/4 of Mycoplasma pneumoniae patients，1/1 of Epstein-Barr virus patients，1/1 of herpes simplex virus patients，and 1/1 of Varicella-zoster virus patients had albuminocytologic dissociation in CSF. Among patients infected with two or more pathogens，62.2% （23/37） showed albuminocytologic dissociation in CSF，while 66.3% （59/89） of GSB patients without antecedent infection had albuminocytologic dissociation in CSF. The positive rates of albuminocytologic dissociation in CSF exhibited significant differences among patients without and with various types of antecedent infections （P = 0.007），whereas no significant difference was noted in CSF protein levels （P > 0.05）. Conclusion The albuminocytologic dissociation in CSF of GBS patients is correlated with the type of antecedent infection. The highest proportion of albuminocytologic dissociation in CSF is observed in patients with Influenza A virus infections.

The autoantigen La protein is an important component of telomerase and a predominantly nuclear phosphoprotein. As a telomerase subunit, La protein associates with the telomerase ribonucleoprotein and influences telomere length. In the reverse transcription, La protein stimulates enzymatic activity and increases repeated addition processivity of telomerase. As nuclear phosphoprotein, La protein binds the 3′ poly(U)‐rich elements of nascent RNA polymerase III transcripts to facilitate its correct folding and maturation. In this work, we identified a La protein homolog (TbLa) from Trypanosoma brucei (T. brucei). We revealed that TbLa interacts with ribosome‐associated protein P34/P37, 40S ribosomal protein SA, and 60S ribosomal subunit L5 in T. brucei. In the interactions between TbLa protein and (P34/P37)/L5/SA, RNA recognition motif (RRM) domain of TbLa was indicated to make the major contribution to the processes. We determined the solution structure of TbLa RRM domain. NMR chemical shift perturbations revealed that the positively charged RNA‐binding pocket of TbLa RRM domain is responsible for its interaction with ribosomal and ribosome‐associated proteins P37/L5/SA. Furthermore, depletion of TbLa affected the maturation process of 5S rRNA and ribosomal assembly, suggesting TbLa protein might play a significant role in the ribosomal biogenesis pathway in T. brucei. Taken together, our results provide a novel insight and structural basis for better understanding the roles of TbLa and RRM domain in ribosomal biogenesis in T. brucei. Database: Structural data are available in the PDB under the accession number 5ZUH. [ABSTRACT FROM AUTHOR]

Centrin is an evolutionarily conserved EF‐hand‐containing protein, which is present in eukaryotic organisms as diverse as algae, yeast, and humans. Centrins are associated with the microtubule‐organizing center and with centrosome‐related structures, such as basal bodies in flagellar and ciliated cells, and the spindle pole body in yeast. Five centrin genes have been identified in Trypanosoma brucei (T. brucei), a protozoan parasite that causes sleeping sickness in humans and nagana in cattle in sub‐Saharan Africa. In the present study, we identified that centrin5 of T. brucei (TbCentrin5) is localized throughout the cytosol and nucleus and enriched in the flagellum. We further identified that TbCentrin5 binds Ca2+ ions with a high affinity and constructed a model of TbCentrin5 bound by Ca2+ ions. Meanwhile, we observed that TbCentrin5 interacts with TbCentrin1, TbCentrin3, and TbCentrin4 and that the interactions are Ca2+‐dependent, suggesting that TbCentrin5 is able to form different complexes with other TbCentrins to participate in relevant cellular processes. Our study provides a foundation for better understanding of the biological roles of TbCentrin5. [ABSTRACT FROM AUTHOR]

Centrin is a conserved calcium-binding protein that plays an important role in diverse cellular biological processes such as ciliogenesis, gene expression, DNA repair and signal transduction. In Trypanosoma brucei , TbCentrin4 is mainly localized in basal bodies and bi-lobe structure, and is involved in the processes coordinating karyokinesis and cytokinesis. In the present study, we solved the solution structure of TbCentrin4 using NMR (nuclear magnetic resonance) spectroscopy. TbCentrin4 contains four EF-hand motifs consisting of eight α-helices. Isothermal titration calorimetry experiment showed that TbCentrin4 has a strong Ca 2+ binding ability. NMR chemical shift perturbation indicated that TbCentrin4 binds to Ca 2+ through its C-terminal domain composed of EF-hand 3 and 4. Meanwhile, we revealed that TbCentrin4 undergoes a conformational change and self-assembly induced by high concentration of Ca 2+ Intriguingly, localization of TbCentrin4 was dispersed or disappeared from basal bodies and the bi-lobe structure when the cells were treated with Ca 2+ in vivo , implying the influence of Ca 2+ on the cellular functions of TbCentrin4. Besides, we observed the interactions between TbCentrin4 and other Tbcentrins and revealed that the interactions are Ca 2+ dependent. Our findings provide a structural basis for better understanding the biological functions of TbCentrin4 in the relevant cellular processes., (© 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)