Different ouabain sensitivities of Na+/K+-ATPase from Poekilocerus bufonius tissues and a possible physiological cost

Al-Robai, Ali A.

doi:10.1016/0305-0491(93)90034-3

Cited by 15 publications

(18 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Duplications of the Na,K-ATPase α-subunit as observed in O. fasciatus evolved at least five times convergently in insects feeding on cardenolide containing plants (Al-Robai 1993;Zhen et al 2012;Dobler et al 2015). While gene duplications may generally have major impacts on fitness due to the altered dosage effect (Kondrashov 2012), we speculate that in this case, the duplications may have been immediately beneficial and thus under positive selection.…”

Section: Discussionmentioning

confidence: 71%

See 1 more Smart Citation

Gene duplications circumvent trade-offs in enzyme function: Insect adaptation to toxic host plants

Dalla¹,

Dobler²

2016

Evolution

View full text Add to dashboard Cite

Herbivorous insects and their adaptations against plant toxins provide striking opportunities to investigate the genetic basis of traits involved in coevolutionary interactions. Target site insensitivity to cardenolides has evolved convergently across six orders of insects, involving identical substitutions in the Na,K-ATPase gene and repeated convergent gene duplications. The large milkweed bug, Oncopeltus fasciatus, has three copies of the Na,K-ATPase α-subunit gene that bear differing numbers of amino acid substitutions in the binding pocket for cardenolides. To analyze the effect of these substitutions on cardenolide resistance and to infer possible trade-offs in gene function, we expressed the cardenolide-sensitive Na,K-ATPase of Drosophila melanogaster in vitro and introduced four distinct combinations of substitutions observed in the three gene copies of O. fasciatus. With an increasing number of substitutions, the sensitivity of the Na,K-ATPase to a standard cardenolide decreased in a stepwise manner. At the same time, the enzyme's overall activity decreased significantly with increasing cardenolide resistance and only the least substituted mimic of the Na,K-ATPase α1C copy maintained activity similar to the wild-type enzyme. Our results suggest that the Na,K-ATPase copies in O. fasciatus have diverged in function, enabling specific adaptations to dietary cardenolides while maintaining the functionality of this critical ion carrier.

show abstract

Section: Discussionmentioning

confidence: 71%

“…Duplications of the Na,K‐ATPase α‐subunit as observed in O. fasciatus evolved at least five times convergently in insects feeding on cardenolide containing plants (Al‐Robai ; Zhen et al. ; Dobler et al.…”

Section: Discussionmentioning

confidence: 99%

Gene duplications circumvent trade-offs in enzyme function: Insect adaptation to toxic host plants

Dalla¹,

Dobler²

2016

Evolution

View full text Add to dashboard Cite

show abstract

“…In contrast, the copy with the highest level of sensitivity to cardenolides should occur in the brain, because a glial sheath surrounding nervous tissue likely functions as a barrier that prevents cardenolides from reaching Na + ,K + -ATPase in the ventral nerve cord (34). In support of this hypothesis, in the Asian grasshopper Poekilocerus bufonius , which has tissue-specific variation in cardenolide sensitivity, Na + ,K + -ATPase in the brain was found to be the most sensitive to ouabain inhibition compared with Na + ,K + -ATPase of the gut and excretory system (35). …”

Section: Differential Expression Of Atpα1 Duplicatesmentioning

confidence: 91%

Parallel Molecular Evolution in an Herbivore Community

Zhen

Aardema

Medina

et al. 2012

Science

266

391

View full text Add to dashboard Cite

Numerous insects have independently evolved the ability to feed on plants that produce toxic secondary compounds called cardenolides and can sequester these compounds for use in their defense. We surveyed the protein target for cardenolides, the alpha subunit of the sodium pump, Na+,K+-ATPase (ATPα), in 14 species that feed on cardenolide-producing plants and 15 outgroups spanning three insect orders. Despite the large number of potential targets for modulating cardenolide sensitivity, amino acid substitutions associated with host-plant specialization are highly clustered, with many parallel substitutions. Additionally, we document four independent duplications of ATPα with convergent tissue-specific expression patterns. We find that unique substitutions are disproportionately associated with recent duplications relative to parallel substitutions. Together, these findings support the hypothesis that adaptation tends to take evolutionary paths that minimize negative pleiotropy.

show abstract

“…Studies of the common milkweed grasshopper Poekilocerus bufonius demonstrated that they were substantially less sensitive to the cardenolide ouabain injections (as measured by LD50) than species that do not feed on milkweed plants [45]. In addition, enzyme inhibition assays performed on extracts from P. bufonius suggest cardenolide insensitivity of Na + , K + -ATPase.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, enzyme inhibition assays performed on extracts from P. bufonius suggest cardenolide insensitivity of Na + , K + -ATPase. In addition, observed heterogeneity among tissues in the degree of cardenolide-insensitivity was interpreted as possible evidence for distinct isoforms of the enzyme in this species [45]. While several species within Pyrgomorphidae show plant-mediated chemical defence, most of the species in the family do not possess aposematic colouration or feed on toxic plants [37], which presents an interesting opportunity to investigate the variation in cardenolide-insensitivity of ATPα.…”

Section: Introductionmentioning

confidence: 99%

Predictability in the evolution of Orthopteran cardenolide insensitivity

Yang

Ravikanthachari

Mariño‐Pérez

et al. 2019

Preprint

View full text Add to dashboard Cite

1The repeated evolutionary specialisation of distantly related insects to cardenolide-containing 2 host plants provides a stunning example of parallel adaptation. Hundreds of herbivorous insect 3 species have independently evolved insensitivity to cardenolides, which are potent inhibitors of 4 the alpha-subunit of Na + , K + -ATPase (ATPα). Previous studies investigating ATPα-mediated 5 cardenolide insensitivity in five insect orders have revealed remarkably high levels of parallelism 6 in the evolution of this trait, including the frequent occurrence of parallel amino acid 7 substitutions at two sites and recurrent episodes of duplication followed by neo-functionalisation. 8Here we add data for a sixth insect order, Orthoptera, which includes an ancient group of highly 9 aposematic cardenolide-sequestering grasshoppers in the family Pyrgomorphidae. We find that 10

show abstract

Different ouabain sensitivities of Na+/K+-ATPase from Poekilocerus bufonius tissues and a possible physiological cost

Cited by 15 publications

References 28 publications

Gene duplications circumvent trade-offs in enzyme function: Insect adaptation to toxic host plants

Gene duplications circumvent trade-offs in enzyme function: Insect adaptation to toxic host plants

Parallel Molecular Evolution in an Herbivore Community

Predictability in the evolution of Orthopteran cardenolide insensitivity

Contact Info

Product

Resources

About