PAZ YEPES , Javier

Los objetivos que nos planteamos al comienzo de esta Tesis fueron contribuir al conocimiento de cómo se produce el transporte de amonio en cianobacterias y cómo se produce la regulación de la expresión de los genes dependientes de NtcA. Para ello nos propusimos: ... n>1. Estudiar los genes amt de las cianobacterias Synechococcus elongatus y...

The Amt proteins constitute a ubiquitous family of transmembrane ammonia channels that permit the net uptake of ammonium by cells. In many organisms, there is more than one amt gene, and these genes are subjected to nitrogen control. The mature Amt protein is a homo- or heterooligomer of three Amt subunits. We previously characterized an amt1...

In the filamentous, heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120, the glnB gene is expressed at considerable levels both in the presence and in the absence of combined nitrogen, although induction, influenced by NtcA, takes place upon combined-nitrogen deprivation likely localized to vegetative cells. In spite of extensive...

The genome of the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 bears a gene cluster including three amt genes that, based on homology of their protein products, we designate amt4, amt1, and amtB. Expression of the three genes took place upon ammonium withdrawal in combined nitrogen-free medium and was NtcA dependent. The genes...