Analysis of al-2 mutations in Neurospora.

The orange pigmentation of the fungus Neurospora crassa is due to the accumulation of the xanthophyll neurosporaxanthin and precursor carotenoids. Two key reactions in the synthesis of these pigments, the formation of phytoene from geranylgeranyl pyrophosphate and the introduction of β cycles in des...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Violeta Díaz-Sánchez, Alejandro F Estrada, Danika Trautmann, M Carmen Limón, Salim Al-Babili, Javier Avalos
Formato:	article
Lenguaje:	EN
Publicado:	Public Library of Science (PLoS) 2011
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/e95bbdeaf1104ed7be1ce6284a1d9c82
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:e95bbdeaf1104ed7be1ce6284a1d9c82
record_format	dspace
spelling	oai:doaj.org-article:e95bbdeaf1104ed7be1ce6284a1d9c822021-11-18T06:49:58ZAnalysis of al-2 mutations in Neurospora.1932-620310.1371/journal.pone.0021948https://doaj.org/article/e95bbdeaf1104ed7be1ce6284a1d9c822011-01-01T00:00:00Zhttps://www.ncbi.nlm.nih.gov/pmc/articles/pmid/21818281/?tool=EBIhttps://doaj.org/toc/1932-6203The orange pigmentation of the fungus Neurospora crassa is due to the accumulation of the xanthophyll neurosporaxanthin and precursor carotenoids. Two key reactions in the synthesis of these pigments, the formation of phytoene from geranylgeranyl pyrophosphate and the introduction of β cycles in desaturated carotenoid products, are catalyzed by two domains of a bifunctional protein, encoded by the gene al-2. We have determined the sequence of nine al-2 mutant alleles and analyzed the carotenoid content in the corresponding strains. One of the mutants is reddish and it is mutated in the cyclase domain of the protein, and the remaining eight mutants are albino and harbor different mutations on the phytoene synthase (PS) domain. Some of the mutations are expected to produce truncated polypeptides. A strain lacking most of the PS domain contained trace amounts of a carotenoid-like pigment, tentatively identified as the squalene desaturation product diapolycopene. In support, trace amounts of this compound were also found in a knock-out mutant for gene al-2, but not in that for gene al-1, coding for the carotene desaturase. The cyclase activity of the AL-2 enzyme from two albino mutants was investigated by heterologous expression in an appropriately engineered E. coli strain. One of the AL-2 enzymes, predictably with only 20% of the PS domain, showed full cyclase activity, suggesting functional independence of both domains. However, the second mutant showed no cyclase activity, indicating that some alterations in the phytoene synthase segment affect the cyclase domain. Expression experiments showed a diminished photoinduction of al-2 transcripts in the al-2 mutants compared to the wild type strain, suggesting a synergic effect between reduced expression and impaired enzymatic activities in the generation of their albino phenotypes.Violeta Díaz-SánchezAlejandro F EstradaDanika TrautmannM Carmen LimónSalim Al-BabiliJavier AvalosPublic Library of Science (PLoS)articleMedicineRScienceQENPLoS ONE, Vol 6, Iss 7, p e21948 (2011)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Violeta Díaz-Sánchez Alejandro F Estrada Danika Trautmann M Carmen Limón Salim Al-Babili Javier Avalos Analysis of al-2 mutations in Neurospora.
description	The orange pigmentation of the fungus Neurospora crassa is due to the accumulation of the xanthophyll neurosporaxanthin and precursor carotenoids. Two key reactions in the synthesis of these pigments, the formation of phytoene from geranylgeranyl pyrophosphate and the introduction of β cycles in desaturated carotenoid products, are catalyzed by two domains of a bifunctional protein, encoded by the gene al-2. We have determined the sequence of nine al-2 mutant alleles and analyzed the carotenoid content in the corresponding strains. One of the mutants is reddish and it is mutated in the cyclase domain of the protein, and the remaining eight mutants are albino and harbor different mutations on the phytoene synthase (PS) domain. Some of the mutations are expected to produce truncated polypeptides. A strain lacking most of the PS domain contained trace amounts of a carotenoid-like pigment, tentatively identified as the squalene desaturation product diapolycopene. In support, trace amounts of this compound were also found in a knock-out mutant for gene al-2, but not in that for gene al-1, coding for the carotene desaturase. The cyclase activity of the AL-2 enzyme from two albino mutants was investigated by heterologous expression in an appropriately engineered E. coli strain. One of the AL-2 enzymes, predictably with only 20% of the PS domain, showed full cyclase activity, suggesting functional independence of both domains. However, the second mutant showed no cyclase activity, indicating that some alterations in the phytoene synthase segment affect the cyclase domain. Expression experiments showed a diminished photoinduction of al-2 transcripts in the al-2 mutants compared to the wild type strain, suggesting a synergic effect between reduced expression and impaired enzymatic activities in the generation of their albino phenotypes.
format	article
author	Violeta Díaz-Sánchez Alejandro F Estrada Danika Trautmann M Carmen Limón Salim Al-Babili Javier Avalos
author_facet	Violeta Díaz-Sánchez Alejandro F Estrada Danika Trautmann M Carmen Limón Salim Al-Babili Javier Avalos
author_sort	Violeta Díaz-Sánchez
title	Analysis of al-2 mutations in Neurospora.
title_short	Analysis of al-2 mutations in Neurospora.
title_full	Analysis of al-2 mutations in Neurospora.
title_fullStr	Analysis of al-2 mutations in Neurospora.
title_full_unstemmed	Analysis of al-2 mutations in Neurospora.
title_sort	analysis of al-2 mutations in neurospora.
publisher	Public Library of Science (PLoS)
publishDate	2011
url	https://doaj.org/article/e95bbdeaf1104ed7be1ce6284a1d9c82
work_keys_str_mv	AT violetadiazsanchez analysisofal2mutationsinneurospora AT alejandrofestrada analysisofal2mutationsinneurospora AT danikatrautmann analysisofal2mutationsinneurospora AT mcarmenlimon analysisofal2mutationsinneurospora AT salimalbabili analysisofal2mutationsinneurospora AT javieravalos analysisofal2mutationsinneurospora
_version_	1718424388498358272

Analysis of al-2 mutations in Neurospora.

Ejemplares similares