Biomaterial Database

Identification and characterization of sea squirt telomerase reverse transcriptase. 2007

Yang Li, and Joel A Yates, and Julian J-L Chen

Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA.

Telomerase is essential for maintaining telomere length and chromosome stability in most eukaryotic organisms. The telomerase ribonucleoprotein complex consists of two essential components, the catalytic telomerase reverse transcriptase protein (TERT) and the intrinsic telomerase RNA. The sea squirts, as urochordates, occupy a key position in the phylogenetic tree of the chordates: they diverged from the other chordates just before the lineage of vertebrates, and thus provide special insight into the origin and evolution of vertebrate genes. Here, we report the cloning and characterization of TERT genes from two sea squirts, Ciona intestinalis and Ciona savignyi. The C. intestinalis TERT (CinTERT) gene encodes 907 amino acids and consists of 17 exons, which are similar to vertebrate TERT genes. The C. savignyi TERT (CsaTERT) gene encodes 843 amino acids, but surprisingly does not contain any introns. Both Ciona TERTs contain all of the reverse transcriptase (RT) motifs (1, 2, A, B, C, D, and E) that are typically present in telomerase and viral RTs. Interestingly, the alignment of Ciona and vertebrate TERT sequences reveals a previously unknown motif, named motif 3, located between motifs 2 and A. The Ciona TERT gene is expressed in all tissues analyzed except the brain and heart. This is the first report of the TERT gene in invertebrate chordates.

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
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
D014561	Urochordata	A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.	Ascidia,Tunicata,Ascidiacea,Ascidians,Sea Squirts,Tunicates,Urochordates,Ascidian,Sea Squirt,Squirt, Sea,Tunicate,Urochordate
D014714	Vertebrates	Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.	Vertebrate
D015870	Gene Expression	The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.	Expression, Gene,Expressions, Gene,Gene Expressions
D016415	Sequence Alignment	The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.	Sequence Homology Determination,Determination, Sequence Homology,Alignment, Sequence,Alignments, Sequence,Determinations, Sequence Homology,Sequence Alignments,Sequence Homology Determinations
D019098	Telomerase	An essential ribonucleoprotein reverse transcriptase that adds telomeric DNA to the ends of eukaryotic CHROMOSOMES.	Telomerase Catalytic Subunit,Telomerase Reverse Transcriptase,Telomerase Reverse Transcriptase Catalytic Subunit,Catalytic Subunit, Telomerase,Reverse Transcriptase, Telomerase,Subunit, Telomerase Catalytic,Transcriptase, Telomerase Reverse