Biomaterial Database

Isolation of a functional ecdysteroid receptor homologue from the ixodid tick Amblyomma americanum (L.). 1997

X Guo, and M A Harmon, and V Laudet, and D J Mangelsdorf, and M J Palmer

Department of Entomology, Oklahoma State University Stillwater 74078, USA.

Ecdysteroids are assumed to be the major steroid hormones in arthropods. However, with the exception of insects and crustaceans, very little is known about ecdysteroid action in other arthropods. To determine if ecdysteriods play a functional role in the ixodid tick, Amblyomma americanum (L.), we isolated cDNAs encoding three presumed ecdysteroid receptor isoforms (AamEcRA1, AamEcRA2, and AamEcRA3) that have common DNA and ligand binding domains linked to distinct amino termini. The DNA and ligand binding domains share an average of 86 and 64% identity, respectively with DNA and ligand binding domains from insect EcR proteins. The amino termini are highly divergent and the AamEcRs lack the 'F' domain found in the insect EcRs. Analysis of AamEcR cDNAs show that processing of the AamEcR gene is complex, producing multiple transcripts with unique 5' and 3' termini as well as splicing variants with incomplete open reading frames. AamEcR mRNA profiles in whole animals and isolated tissues are consistent with complex regulation of AamEcR expression. We also examined the ability of AamEcRA1, when paired with an AamRXR, to activate transcription of an ecdysone response element containing reporter, and demonstrate that the AamEcR gene encodes a functional ecdysteroid receptor.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010802	Phylogeny	The relationships of groups of organisms as reflected by their genetic makeup.	Community Phylogenetics,Molecular Phylogenetics,Phylogenetic Analyses,Phylogenetic Analysis,Phylogenetic Clustering,Phylogenetic Comparative Analysis,Phylogenetic Comparative Methods,Phylogenetic Distance,Phylogenetic Generalized Least Squares,Phylogenetic Groups,Phylogenetic Incongruence,Phylogenetic Inference,Phylogenetic Networks,Phylogenetic Reconstruction,Phylogenetic Relatedness,Phylogenetic Relationships,Phylogenetic Signal,Phylogenetic Structure,Phylogenetic Tree,Phylogenetic Trees,Phylogenomics,Analyse, Phylogenetic,Analysis, Phylogenetic,Analysis, Phylogenetic Comparative,Clustering, Phylogenetic,Community Phylogenetic,Comparative Analysis, Phylogenetic,Comparative Method, Phylogenetic,Distance, Phylogenetic,Group, Phylogenetic,Incongruence, Phylogenetic,Inference, Phylogenetic,Method, Phylogenetic Comparative,Molecular Phylogenetic,Network, Phylogenetic,Phylogenetic Analyse,Phylogenetic Clusterings,Phylogenetic Comparative Analyses,Phylogenetic Comparative Method,Phylogenetic Distances,Phylogenetic Group,Phylogenetic Incongruences,Phylogenetic Inferences,Phylogenetic Network,Phylogenetic Reconstructions,Phylogenetic Relatednesses,Phylogenetic Relationship,Phylogenetic Signals,Phylogenetic Structures,Phylogenetic, Community,Phylogenetic, Molecular,Phylogenies,Phylogenomic,Reconstruction, Phylogenetic,Relatedness, Phylogenetic,Relationship, Phylogenetic,Signal, Phylogenetic,Structure, Phylogenetic,Tree, Phylogenetic
D011987	Receptors, Steroid	Proteins found usually in the cytoplasm or nucleus that specifically bind steroid hormones and trigger changes influencing the behavior of cells. The steroid receptor-steroid hormone complex regulates the transcription of specific genes.	Corticosteroid Receptors,Receptors, Corticosteroid,Steroid Receptors,Corticosteroid Receptor,Receptors, Steroids,Steroid Receptor,Receptor, Corticosteroid,Receptor, Steroid,Steroids Receptors
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D004441	Ecdysterone	A steroid hormone that regulates the processes of MOLTING or ecdysis in insects. Ecdysterone is the 20-hydroxylated ECDYSONE.	20-Hydroxyecdysone,Beta-Ecdysone,Crustecdysone,20 Hydroxyecdysone,Beta Ecdysone
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012333	RNA, Messenger	RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.	Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated