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T Starke

Publications and source records attributed to T Starke.

8 recordsLinked to original sources
PubMed1993

A conserved intron in the V-ATPase A subunit genes of plants and algae.

Amplification and sequencing of part of the coding regions of the catalytic V-type ATPase subunit shows the presence of (at least) two genes in all land plants as well as the conservative insertion of a noncoding sequence. The two genes exhibit a coding region of the same length but differ in the number of nucleotides present in the intron. The latter is surprisingly conserved suggesting the presence of functional constraints on the intron sequences. The findings presented in this report indicate that introns from plants and animals are characterized by different internal structural elements.

Adenosine Triphosphatases↗
PubMed1992

Evolution of structure and function of V-ATPases.

Proton pumping ATPases/ATPsynthases are found in all groups of present-day organisms. The structure of V- and F-type ATPases/ATP synthases is very conserved throughout evolution. Sequence analysis shows that the V- and F-type ATPases evolved from the same enzyme already present in the last common ancestor of all known extant life forms. The catalytic and noncatalytic subunits found in the dissociable head groups of the V/F-type ATPases are paralogous subunits, i.e., these two types of subunits evolved from a common ancestral gene. The gene duplication giving rise to these two genes (i.e., encoding the catalytic and noncatalytic subunits) predates the time of the last common ancestor. Mapping of gene duplication events that occurred in the evolution of the proteolipid, the noncatalytic and the catalytic subunits, onto the tree of life leads to a prediction for the likely subunit structure of the encoded ATPases. A correlation between structure and function of V/F-ATPases has been established for present-day organisms. Implications resulting from this correlation for the bioenergetics operative in proto-eukaryotes and in the last common ancestor are presented. The similarities of the V/F-ATPase subunits to an ATPase-like protein that was implicated to play a role in flagellar assembly are evaluated. Different V-ATPase isoforms have been detected in some higher eukaryotes. These data are analyzed with respect to the possible function of the different isoforms (tissue specific, organelle specific) and with respect to the point in their evolution when these gene duplications giving rise to the isoforms had occurred, i.e., how far these isoforms are distributed.

Amino Acid Sequence↗
PubMed1992

Evolution and isoforms of V-ATPase subunits.

The structure of V- and F-ATPases/ATP synthases is remarkably conserved throughout evolution. Sequence analyses show that the V- and F-ATPases evolved from the same enzyme that was already present in the last common ancestor of all known extant life forms. The catalytic and non-catalytic subunits found in the dissociable head groups of both V-ATPases and F-ATPases are paralogous subunits, i.e. these two types of subunits evolved from a common ancestral gene. The gene duplication giving rise to these two genes (i.e. those encoding the catalytic and non-catalytic subunits) pre-dates the time of the last common ancestor. Similarities between the V- and F-ATPase subunits and an ATPase-like protein that is implicated in flagellar assembly are evaluated with regard to the early evolution of ATPases. Mapping of gene duplication events that occurred in the evolution of the proteolipid, the non-catalytic and the catalytic subunits onto the tree of life leads to a prediction of the likely quaternary structure of the encoded ATPases. The phylogenetic implications of V-ATPases found in eubacteria are discussed. Different V-ATPase isoforms have been detected in some higher eukaryotes, whereas others were shown to have only a single gene encoding the catalytic V-ATPase subunit. These data are analyzed with respect to the possible function of the different isoforms (tissue-specific, organelle-specific). The point in evolution at which the different isoforms arose is mapped by phylogenetic analysis.

Adenosine Triphosphatases↗
PubMedDate not supplied

Two separate genes encode the catalytic 70 kDa V-ATPase subunit in Psilotum and Equisetum.

Vacuolar type ATPases have been found on various endomembranes of eukaryotic cells, e.g. lysosomes, chromaffin granules, vesicles derived from the Golgi apparatus, endosomes and vacuoles. Although this ATPase type is targeted to different compartments in one cell, only one gene for each subunit had been found per genome. Using PCR across intron-exon boundaries we show that two different genes encode the catalytic subunit of the V-ATPase in Psilotum nudum and Equisetum arvense. The substitution rates for the three codon positions and the intervening sequences show that in Psilotum both genes are transcribed and are under selection pressure, however, this seems not to be the case for Equisetum. The relatively high similarity between the two genes found in each species as compared to the interspecies similarities suggest that for some time after the gene duplication had occurred the two copies were subject to gene conversion mechanisms. An unexpected degree of conservation of the intervening sequences themselves is noted and statistically verified, however, no structural constraints that could explain these findings were detected.

Adenosine Triphosphatases↗