Cellular costs in the synthesis of glycan information*

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 an earlier work, we brought out the tradeoffs in number of Golgi cisternae, number of glycosylation enzymes and their specificity, required to synthesize a prescribed complex target glycan distribution within a given fidelity. In this work we study how non equilibrium driving in transport and reaction rates affect fidelity of the synthesized glycan distribution.