Accelerated molecular evolution of insect orthologues ofERG28/C14orf1: A link with ecdysteroid metabolism?

Veitia, Reiner A.; Hurst, Laurence D.

doi:10.1007/bf02811414

Cited by 6 publications

(8 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, further evidence of sequence relatedness was gathered using Psi-BLAST with the yeast sequence against the Metazoa division of Genbank [35]. We included in the iterations the very divergent sequence CG17270 of D. melanogaster , which is the ortholog of ERG28p according to our previous results [23]. This allowed us to detect C14C10.6 as a signinficant hit (S = 120 bits and E = 10 −27 ).…”

Section: Resultsmentioning

confidence: 99%

“…In a previous paper, given the structural similarity between cholesterol and ecdysteroids, we had proposed that divergent ERGp orthologs might somehow participate in the synthesis of the latter [23]. We have therefore assessed the expressional correlation between candidate genes involved in this process: Dare1 /CG12390 [43], Jhamt [44] and Start1 [45], with dLBR and CG1998 .…”

Section: Resultsmentioning

confidence: 99%

“…This makes sense, knowing that Drosophila is unable to synthesize cholesterol. However, in a previous work we have shown that Drosophila contains an ERG28 ortholog that has undergone a process of acceleration in its evolution, and is undetectable using the current techniques for ortholog detection by sequence homology [23]. Thus, here we have revisited this question for both C. elegans and D. melanogaster , not only for ERG28 , but most of the genes/enzymes involved in the sterol synthesis pathway, in the light of new genomic and functional data.…”

Section: Introductionmentioning

confidence: 95%

See 2 more Smart Citations

Preservation of Genes Involved in Sterol Metabolism in Cholesterol Auxotrophs: Facts and Hypotheses

2008

Self Cite

View full text Add to dashboard Cite

BackgroundIt is known that primary sequences of enzymes involved in sterol biosynthesis are well conserved in organisms that produce sterols de novo. However, we provide evidence for a preservation of the corresponding genes in two animals unable to synthesize cholesterol (auxotrophs): Drosophila melanogaster and Caenorhabditis elegans.Principal FindingsWe have been able to detect bona fide orthologs of several ERG genes in both organisms using a series of complementary approaches. We have detected strong sequence divergence between the orthologs of the nematode and of the fruitfly; they are also very divergent with respect to the orthologs in organisms able to synthesize sterols de novo (prototrophs). Interestingly, the orthologs in both the nematode and the fruitfly are still under selective pressure. It is possible that these genes, which are not involved in cholesterol synthesis anymore, have been recruited to perform different new functions. We propose a more parsimonious way to explain their accelerated evolution and subsequent stabilization. The products of ERG genes in prototrophs might be involved in several biological roles, in addition to sterol synthesis. In the case of the nematode and the fruitfly, the relevant genes would have lost their ancestral function in cholesterogenesis but would have retained the other function(s), which keep them under pressure.ConclusionsBy exploiting microarray data we have noticed a strong expressional correlation between the orthologs of ERG24 and ERG25 in D. melanogaster and genes encoding factors involved in intracellular protein trafficking and folding and with Start1 involved in ecdysteroid synthesis. These potential functional connections are worth being explored not only in Drosophila, but also in Caenorhabditis as well as in sterol prototrophs.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

Preservation of Genes Involved in Sterol Metabolism in Cholesterol Auxotrophs: Facts and Hypotheses

2008

Self Cite

View full text Add to dashboard Cite

show abstract

“…Because Erg28p is included in the Hmg2p-induced structures, it could have a direct role on the formation or function of these membrane arrays. Erg28p, like HMGR, is highly conserved and loss of Erg28p results in sterol deficiencies across species (for examples, see Gachotte et al, 2001;Veitia and Hurst, 2001). Last, previous work demonstrated that human testis cells (Veitia et al, 1999) and adrenal cortical cells (Hu et al, 2000) both have increased expression of human Erg28p, as is observed for HMGR (for review, see Federovitch et al, 2005).…”

Section: Discussionmentioning

confidence: 98%

Genetic and Structural Analysis of Hmg2p-induced Endoplasmic Reticulum Remodeling inSaccharomyces cerevisiae

Federovitch

Jones

Tong

et al. 2008

MBoC

View full text Add to dashboard Cite

The endoplasmic reticulum (ER) is highly plastic, and increased expression of distinct single ER-resident membrane proteins, such as HMG-CoA reductase (HMGR), can induce a dramatic restructuring of ER membranes into highly organized arrays. Studies on the ER-remodeling behavior of the two yeast HMGR isozymes, Hmg1p and Hmg2p, suggest that they could be mechanistically distinct. We examined the features of Hmg2p required to generate its characteristic structures, and we found that the molecular requirements are similar to those of Hmg1p. However, the structures generated by Hmg1p and Hmg2p have distinct cell biological features determined by the transmembrane regions of the proteins. In parallel, we conducted a genetic screen to identify HER genes (required for Hmg2p-induced ER Remodeling), further confirming that the mechanisms of membrane reorganization by these two proteins are distinct because most of the HER genes were required for Hmg2p but not Hmg1p-induced ER remodeling. One of the HER genes identified was PSD1, which encodes the phospholipid biosynthetic enzyme phosphatidylserine decarboxylase. This direct connection to phospholipid biosynthesis prompted a more detailed examination of the effects of Hmg2p on phospholipid mutants and composition. Our analysis revealed that overexpression of Hmg2p caused significant and specific growth defects in nulls of the methylation pathway for phosphatidylcholine biosynthesis that includes the Psd1p enzyme. Furthermore, increased expression of Hmg2p altered the composition of cellular phospholipids in a manner that implied a role for PSD1. These phospholipid effects, unlike Hmg2p-induced ER remodeling, required the enzymatic activity of Hmg2p. Together, our results indicate that, although related, Hmg2p-and Hmg1p-induced ER remodeling are mechanistically distinct.

show abstract

“…Our knowledge of the evolution of enzymes involved in steroid biosynthesis is still fragmentary. Veitia and Hurst (2001) suggested that insects, which are auxotrophs for sterols, would use some of the genes involved in sterol biosynthesis for ecdysteroid biosynthesis, but this hypothesis requires further substantiation. Whether some invertebrates synthesize both vertebrate-type steroids and ecdysteroids is also a challenging question in the field of steroid evolution.…”

Section: Biosynthesismentioning

confidence: 96%

Steroids in aquatic invertebrates

2007

View full text Add to dashboard Cite

Steroid molecules are present in all invertebrates, and some of them have established hormonal roles: this is the case for ecdysteroids in arthropods and, to a lesser extent, for vertebrate-type steroids in molluscs. Steroids are not only hormones, they may also fulfill many other functions in chemical communication, chemical defense or even digestive physiology. The increasing occurrence of endocrine disruption problems caused by environmental pollutants, which interfere in particular with reproductive physiology of vertebrates but also of invertebrates has made necessary to better understand the endocrine physiology of the latter and the role of steroids in these processes. So many attempts are being made to better understand the endocrine roles of steroids in arthropods and molluscs, and to establish whether they also fulfill similar functions in other invertebrate phyla. At the moment, both the precise identification of these steroids, the determination of their origin (endogenous versus exogenous) and of their mechanism of action are under active investigation. This research takes profit of the development of genome sequencing programs on many invertebrate species, which allow the identification of receptors and/or biosynthetic enzymes, when related to their vertebrate counterparts, but the story is not so simple, as will be exemplified by estrogen receptors of molluscs.

show abstract

Accelerated molecular evolution of insect orthologues ofERG28/C14orf1: A link with ecdysteroid metabolism?

Cited by 6 publications

References 13 publications

Preservation of Genes Involved in Sterol Metabolism in Cholesterol Auxotrophs: Facts and Hypotheses

Preservation of Genes Involved in Sterol Metabolism in Cholesterol Auxotrophs: Facts and Hypotheses

Genetic and Structural Analysis of Hmg2p-induced Endoplasmic Reticulum Remodeling inSaccharomyces cerevisiae

Steroids in aquatic invertebrates

Contact Info

Product

Resources

About