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35Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is considered a 36 multifunctional protein with defined functions in numerous mammalian cellular processes. 37 GAPDH functional diversity depends on various factors such as covalent modifications, 38 subcellular localization, oligomeric state and intracellular concentration of substrates or 39 ligands, as well as protein-protein interactions. In bacteria, alternative GAPDH functions 40 have been associated with its extracellular location in pathogens or probiotics. In this study, 41 new intracellular functions of E. coli GAPDH were investigated following a proteomic 42 approach aimed at identifying interacting partners using in vivo formaldehyde cross-linking 43 followed by mass spectrometry. The identified proteins were involved in metabolic 44 processes, protein synthesis and folding or DNA repair. Some interacting proteins were also 45 identified in immunopurification experiments in the absence of cross-linking. Pull-down 46 experiments and overlay immunoblotting were performed to further characterize the 47 interaction with phosphoglycolate phosphatase (Gph). This enzyme is involved in the 48 metabolism of 2-phosphoglycolate formed in the DNA repair of 3'-phosphoglycolate ends 49 generated by bleomycin damage. We show that interaction between Gph and GAPDH 50 increases in cells challenged with bleomycin, suggesting involvement of GAPDH in 51 cellular processes linked to DNA repair mechanisms. 52 53

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional protein with diverse biological functions in human cells. In bacteria, moonlighting GAPDH functions have only been described for the secreted protein in pathogens or probiotics. At the intracellular level, we previously reported the interaction of Escherichia coli GAPDH with phosphoglycolate phosphatase, a protein involved in the metabolism of the DNA repair product 2-phosphoglycolate, thus suggesting a putative role of GAPDH in DNA repair processes. Here, we provide evidence that GAPDH is required for the efficient repair of DNA lesions in E. coli. We show that GAPDH-deficient cells are more sensitive to bleomycin or methyl methanesulfonate. In cells challenged with these genotoxic agents, GAPDH deficiency results in reduced cell viability and filamentous growth. In addition, the gapA knockout mutant accumulates a higher number of spontaneous abasic sites and displays higher spontaneous mutation frequencies than the parental strain. Pull-down experiments in different genetic backgrounds show interaction between GAPDH and enzymes of the base excision repair pathway, namely the AP-endonuclease Endo IV and uracil DNA glycosylase. This finding suggests that GAPDH is a component of a protein complex dedicated to the maintenance of genomic DNA integrity. Our results also show interaction of GAPDH with the single-stranded DNA binding protein. This interaction may recruit GAPDH to the repair sites and implicates GAPDH in DNA repair pathways activated by profuse DNA damage, such as homologous recombination or the SOS response.

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-In Brazil, species of the genus Liriomyza are widely distributed and have economic importance as they cause damage to at least 14 plant families, especially Solanaceae, Cucurbitaceae, Asteraceae, and Fabaceae. Studies suggest existence of a species complex within this genus, based on the presence of morphological similarities among the species Liriomyza trifolii (Burgess), L. sativae Blanchard and L. huidobrensis (Blanchard). The present study aimed to use DNA barcoding to establish new distribution records of L. sativae in distinct regions in Brazil, determine intra-and inter-population genetic diversity, and reconstruct the phylogeny of Liriomyza species using the DNA barcode sequences. Identity values were between 97% and 99%, confirming that all the examined Brazilian populations belonged to the species L. sativae. Phylogenetic analyses indicated the presence of a single clade of L. sativae, composed of seven populations. Intra-population analysis on individuals of these populations indicated low levels of nucleotide and haplotype diversity. The haplotype network indicated presence of only 14 haplotypes distributed among the Brazilian populations. The genetic similarities shared by the Brazilian populations of L. sativae suggest that these populations are closely related. Genetic patterns observed among populations of L. sativae might be associated with bottleneck events or founder effect during establishment of this leafminer in Brazil.Keywords: Cryptic species. DNA barcoding. Population genetics. IDENTIFICAÇÃO MOLECULAR DE Liriomyza sp. NAS REGIÕES NORDESTE E SUDESTE DO BRASILRESUMO -No Brasil, as espécies do gênero Liriomyza têm importância econômica e são amplamente distribuídos no país, causando danos a pelo menos 14 famílias de plantas, especialmente Solanaceae, Cucurbitaceae, Asteraceae e Fabaceae. Estudos sugerem a existência de um complexo de espécies dentro deste gênero com base na presença de semelhança morfológica nas espécies Liriomyza trifolii (Burgess), L. sativae (Blanchard) e L. huidobrensis (Blanchard). Este estudo teve como objetivo empregar o DNA Barcode em novas áreas para estabelecer novos registros de Liriomyza sativae no Brasil e também a determinação da diversidade genética intra e interpopulacional, e reconstruir a filogenia das espécies Liriomyza utilizando sequências do DNA barcode. Os valores de identidade foram entre 97% a 99%, confirmando que as todas as populações brasileiras avaliadas pertencem à espécie L. sativae. A análise filogenética indicou a presença de um único clado de L. sativae composto pelas sete populações. A análise intrapopulacional indicou níveis baixos de diversidade nucleotidica e haplótipica de indivíduos dessas populações. A rede de haplótipos indicou a presença de apenas 14 haplótipos distribuídos entre populações brasileiras. As semelhanças genéticas compartilhadas pelas populações brasileiras de L. sativae sugere que essas populações estão intimamente relacionados. Os padrões genéticos observados em populações de L. sativae pode estar associad...

The conformational stability and the folding process of alpha, beta and Psi bovine trypsin at pH 3.0 followed by circular dichroism (CD) and size exclusion in HPLC have been analyzed as a function of urea concentration. The thermodynamic stability for a and b are deltaG = 15.91 +/- 0.28 kcal/mol, deltaG = 15.54 +/- 2.39 kcal/mol. respectively, and y trypsin is deltaG = 16.10 +/- 2.51 kcal/mol. The transition curves for alpha, beta and Psi forms suggest a molten globule state.

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