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Dave Anderson

Publications and source records attributed to Dave Anderson.

5 recordsLinked to original sources
PubMed2006

Characterization of hARD2, a processed hARD1 gene duplicate, encoding a human protein N-alpha-acetyltransferase.

BACKGROUND: Protein acetylation is increasingly recognized as an important mechanism regulating a variety of cellular functions. Several human protein acetyltransferases have been characterized, most of them catalyzing epsilon-acetylation of histones and transcription factors. We recently described the human protein acetyltransferase hARD1 (human Arrest Defective 1). hARD1 interacts with NATH (N-Acetyl Transferase Human) forming a complex expressing protein N-terminal alpha-acetylation activity. RESULTS: We here describe a human protein, hARD2, with 81 % sequence identity to hARD1. The gene encoding hARD2 most likely originates from a eutherian mammal specific retrotransposition event. hARD2 mRNA and protein are expressed in several human cell lines. Immunoprecipitation experiments show that hARD2 protein potentially interacts with NATH, suggesting that hARD2-NATH complexes may be responsible for protein N-alpha-acetylation in human cells. In NB4 cells undergoing retinoic acid mediated differentiation, the level of endogenous hARD1 and NATH protein decreases while the level of hARD2 protein is stable. CONCLUSION: A human protein N-alpha-acetyltransferase is herein described. ARD2 potentially complements the functions of ARD1, adding more flexibility and complexity to protein N-alpha-acetylation in human cells as compared to lower organisms which only have one ARD.

Acetylation↗
PubMed2006

Cloning and characterization of hNAT5/hSAN: an evolutionarily conserved component of the NatA protein N-alpha-acetyltransferase complex.

The human hARD1-NATH complex, cotranslationally acetylating the alpha-amino groups of proteins, was recently described. In S. cerevisiae and D. melanogaster this NatA complex contains a third subunit, Nat5p or San, respectively. Based on phylogenetic analyses and database searches, we here describe the human homologue, hNAT5, of these proteins. RT-PCR experiments demonstrated that hNat5 mRNA was expressed in several human cell lines. The candidacy of hNAT5 as a third subunit of the hARD1-NATH complex was investigated using anti-NATH or anti-hARD1 in co-immunoprecipitation experiments followed by Mass Spectrometry analysis of tryptic peptides. Oligopeptides specific for hNAT5 were identified. This verified the expression of endogenous hNAT5 protein in human cells and also identified hNAT5 as a NATH and hARD1 interacting partner. hNAT5 localized to the cytoplasm in accordance with hNAT5-hARD1-NATH complexes playing a role in cotranslational N-alpha-acetylation. Sequence alignment revealed a high degree of similarity of the NAT5 protein between species supporting its conserved role as a part of the complex. The predicted acetyltransferase domain within hNAT5 suggested that this protein, like hARD1, is an enzymatically active component. In summary, we present the first description of the human homologue of Nat5p/San, hNAT5, the third component of the human NatA N-alpha-acetyltransferase complex.

Acetyltransferases↗
PubMed2005

Identification and characterization of the human ARD1-NATH protein acetyltransferase complex.

Protein acetyltransferases and deacetylases have been implicated in oncogenesis, apoptosis and cell cycle regulation. Most of the protein acetyltransferases described acetylate epsilon-amino groups of lysine residues within proteins. Mouse ARD1 (homologue of yeast Ard1p, where Ard1p stands for arrest defective 1 protein) is the only known protein acetyltransferase catalysing acetylation of proteins at both alpha-(N-terminus) and epsilon-amino groups. Yeast Ard1p interacts with Nat1p (N-acetyltransferase 1 protein) to form a functional NAT (N-acetyltransferase). We now describe the human homologue of Nat1p, NATH (NAT human), as the partner of the hARD1 (human ARD1) protein. Included in the characterization of the NATH and hARD1 proteins is the following: (i) endogenous NATH and hARD1 proteins are expressed in human epithelial, glioma and promyelocytic cell lines; (ii) NATH and hARD1 form a stable complex, as investigated by reciprocal immunoprecipitations followed by MS analysis; (iii) NATH-hARD1 complex expresses N-terminal acetylation activity; (iv) NATH and hARD1 interact with ribosomal subunits, indicating a co-translational acetyltransferase function; (v) NATH is localized in the cytoplasm, whereas hARD1 localizes both to the cytoplasm and nucleus; (vi) hARD1 partially co-localizes in nuclear spots with the transcription factor HIF-1alpha (hypoxia-inducible factor 1alpha), a known epsilon-amino substrate of ARD1; (vii) NATH and hARD1 are cleaved during apoptosis, resulting in a decreased NAT activity. This study identifies the human homologues of the yeast Ard1p and Nat1p proteins and presents new aspects of the NATH and hARD1 proteins relative to their yeast homologues.

Acetylation↗
PubMed2004

Efficient testing of segmented aspherical mirrors by use of a reference plate and computer-generated holograms. II. Case study, error analysis, and experimental validation.

Segmented mirrors present unique challenges to fabrication and testing that are absent for monolithic optics. Since traditional asphere tests do not address segmented optics adequately, we validate a previously developed method to test large quantities of segments accurately, quickly, and economically. In this test, the aspheric shape of each segment is controlled to high accuracy by use of computer-generated holograms, and the radius of curvature is tightly controlled by use of the reference plate. In an adjoining paper [Appl Opt 43, 5303 (2004)] we developed the theory for this test, and now we present a complete system design and optimization for measuring the 1.4-m segments from a 30-m F/1 primary. A complete tolerance analysis predicts a test accuracy of 4.8-nm rms surface and excellent accuracy for controlling the geometry of the segment. In addition, a laboratory demonstration using 30-cm optics is presented that demonstrated 3.9-nm rms surface accuracy.

Journal Article↗