RESUMO
cpQSOx1 is a member of the QSOx family of proteins, expressed in the guinea pig (Cavia porcellus) and ortholog of the rat rQSOx1. In this study, in vitro experiments were conducted and showed that, as other member of this family, cpQSOx1 has a sulfydryl oxidase activity, and is a secreted protein. Then, the expression of this enzyme was researched in the guinea pig brain, as very little information exists yet on the expression of QSOx family members in the central nervous system. By immunohistochemistry, RT-PCR and in situ hybridization, cpQSOx1 is synthesized by neurons throughout the whole guinea pig central nervous system. Reticular structures as the basal forebrain, reticular thalamic nucleus and reticular nuclei of the brainstem contained the densest labeling. These results are discussed in terms of putative roles of this protein in synaptic strengthening and in redox activities.
Assuntos
Sistema Nervoso Central/enzimologia , Oxirredutases/metabolismo , Animais , Linhagem Celular Tumoral , Cobaias , Humanos , Imuno-Histoquímica , Hibridização In Situ , Neurônios/citologia , Neurônios/enzimologia , Oxirredução , Oxirredutases/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Using differential hybridization of a guinea pig endometrial cell cDNA library, a potentially negatively estrogen-regulated gene, SOX-3, was isolated. According to the nucleotide and protein sequence similarities, SOx-3 belonged to the FAD-linked sulfhydryl oxidase family containing the egg white sulfhydryl oxidase, the rat seminal vesicle sulfhydryl oxidase-2 SOx-2, the quiescence-inducible protein hQ6. The SOX-3 transcript in the guinea pig as well as 5 different mRNAs in human tissues appeared differentially expressed in the tissues studied. In secondary endometrial cell culture, the SOX-3 mRNA level increased during a serum depletion-induced quiescence, decreased when cells enter the G1 phase after serum stimulation, and was restored during the S and G2/M phases. Thus, SOX-3 could be implicated in the negative cell cycle control. The SOx-3 protein appeared to be specific of epithelial cells in the uterus. Its expression level varied during the estrus cycle in the guinea pig, suggesting a regulation by steroid hormones.
Assuntos
Estro/metabolismo , Oxirredutases/isolamento & purificação , Útero/enzimologia , Sequência de Aminoácidos , Animais , Ciclo Celular/fisiologia , DNA Complementar/análise , Proteínas de Ligação a DNA/química , Endométrio/metabolismo , Estrogênios/farmacologia , Feminino , Regulação Enzimológica da Expressão Gênica , Biblioteca Gênica , Cobaias , Proteínas HMGB , Humanos , Dados de Sequência Molecular , Proteínas Nucleares/química , Especificidade de Órgãos , Oxirredutases/biossíntese , Oxirredutases/genética , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Fatores de Transcrição SOXB1 , Homologia de Sequência de Aminoácidos , Fatores de Transcrição , Útero/citologiaRESUMO
We have isolated, in guinea-pig endometrial cells, an estrogen-induced 1.8 kb RNA called gec1. Screening of a guinea-pig genomic library led to identification of gec1 gene consisting of 4 exons and 3 introns. Exon 1 contains the 5'UTR and the ATG initiation codon. A guinea-pig gec1 cDNA was obtained by 5'-RACE. The 351 bp coding sequence shares 76.8% identity with that of the human GABARAP 924 bp cDNA while UTRs of the two cDNAs differ. A gec1 probe from the 3'UTR revealed a 1.9 kb mRNA in human tissues and a human GEC1 cDNA was isolated from placenta. Its coding sequence shares 93 and 79% identity with that of guinea-pig gec1 and human GABARAP, respectively. The human and guinea-pig GEC1 proteins have 100% identity. GEC1 and GABARAP proteins have 87% identity and N terminus featuring a tubulin binding motif. Thus, estrogen-regulated gec1 is a new gene which could encode a microtubule-associated protein.