PT  - JOURNAL ARTICLE
AU  - Alkesh Yadav
AU  - Quentin Vagne
AU  - Pierre Sens
AU  - Garud Iyengar
AU  - Madan Rao
TI  - Glycan processing in the Golgi – optimal information coding and constraints on cisternal number and enzyme specificity
AID  - 10.1101/2020.05.18.101444
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.05.18.101444
4099  - http://biorxiv.org/content/early/2020/05/19/2020.05.18.101444.short
4100  - http://biorxiv.org/content/early/2020/05/19/2020.05.18.101444.full
AB  - Many proteins that undergo sequential enzymatic modification in the Golgi cisternae are displayed at the plasma membrane as cell identity markers. The modified proteins, called glycans, represent a molecular code. The fidelity of this glycan code is measured by how accurately the glycan synthesis machinery realises the desired target glycan distribution for a particular cell type and niche. In this paper, we quantitatively analyse the tradeoffs between the number of cisternae and the number and specificity of enzymes, in order to synthesize a prescribed target glycan distribution of a certain complexity. We find that to synthesize complex distributions, such as those observed in real cells, one needs to have multiple cisternae and precise enzyme partitioning in the Golgi. Additionally, for fixed number of enzymes and cisternae, there is an optimal level of specificity of enzymes that achieves the target distribution with high fidelity. Our results show how the complexity of the target glycan distribution places functional constraints on the Golgi cisternal number and enzyme specificity.Competing Interest StatementThe authors have declared no competing interest.