Biology subjects

Surmacz, L.

Publications and source records attributed to Surmacz, L..

2 recordsLinked to original sources

bioRxiv2020

GWAS analysis combined with QTL mapping identify CPT3 and ABH as genes underlying dolichol accumulation in Arabidopsis

Dolichols (Dols), ubiquitous components of living organisms, are indispensable for cell survival. In plants, as well as other eukaryotes, Dols are crucial for posttranslational protein glycosylation, aberration of which leads to fatal metabolic disorders in humans. Until now, the regulatory mechanisms underlying Dol accumulation remain elusive. In this report, we have analyzed the natural variation of the accumulation of Dols and six other isoprenoids between 120 Arabidopsis thaliana accessions. Subsequently, by combining QTL and GWAS approaches, we have identified several candidate genes involved in the accumulation of Dols, polyprenols, plastoquinone, and phytosterols. The role of two genes implicated in the accumulation of major Dols in Arabidopsis - the AT2G17570 gene encoding a long searched for cis-prenyltransferase (CPT3) and the AT1G52460 gene encoding an alpha-beta hydrolase (ABH) - is experimentally confirmed. These data will help to generate Dol-enriched plants which might serve as a remedy for Dol-deficiency in humans.

genomics↗

bioRxiv2020

Structural elucidation of the heterodimeric cis-prenyltransferase NgBR/DHDDS complex reveals novel insights in regulation of protein glycosylation

Cis-prenyltransferase (cis-PTase) catalyzes the rate-limiting step in the synthesis of glycosyl carrier lipids required for protein glycosylation in the lumen of endoplasmic reticulum. Here we report the crystal structure of the human NgBR/DHDDS complex, which represents the first atomic resolution structure for any heterodimeric cis-PTase. The crystal structure sheds light on how NgBR stabilizes DHDDS through dimerization, participates in the enzymes active site through its C-terminal -RXG- motif, and how phospholipids markedly stimulate cis-PTase activity. Comparison of NgBR/DHDDS with homodimeric cis-PTase structures leads to a model where the elongating isoprene chain extends beyond the enzymes active site tunnel, and an insert within the 3 helix helps to stabilize this energetically unfavorable state to enable long chain synthesis to occur. These data provide unique insights into how heterodimeric cis-PTases have evolved from their ancestral, homodimeric forms to fulfill their function in long chain polyprenol synthesis.

biochemistry↗