Pom1 gradient buffering through intermolecular auto‐phosphorylation. Issue 7 (6th July 2015)

• Record Type: Journal Article
• Authors: Hersch, Micha; Hachet, Olivier; Dalessi, Sascha; Ullal, Pranav; Bhatia, Payal; Bergmann, Sven; Martin, Sophie G
• Is Part Of: Molecular systems biology. Volume 11:Issue 7(2015:Jul.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2015-07-06
• Subjects: Molecular biology -- Periodicals; Systems biology -- Periodicals; 572.8
• DOI: 10.15252/msb.20145996
• Languages: English
• ISSNs: 1744-4292

Abstract

<abstract abstract-type="main" id="msb145996-abs-0001"> <title>Abstract</title> <p>Concentration gradients provide spatial information for tissue patterning and cell organization, and their robustness under natural fluctuations is an evolutionary advantage. In rod‐shaped <italic>Schizosaccharomyces pombe</italic> cells, the DYRK‐family kinase Pom1 gradients control cell division timing and placement. Upon dephosphorylation by a Tea4‐phosphatase complex, Pom1 associates with the plasma membrane at cell poles, where it diffuses and detaches upon auto‐phosphorylation. Here, we demonstrate that Pom1 auto‐phosphorylates intermolecularly, both <italic>in vitro</italic> and <italic>in vivo</italic>, which confers robustness to the gradient. Quantitative imaging reveals this robustness through two system's properties: The Pom1 gradient amplitude is inversely correlated with its decay length and is buffered against fluctuations in Tea4 levels. A theoretical model of Pom1 gradient formation through intermolecular auto‐phosphorylation predicts both properties qualitatively and quantitatively. This provides a telling example where gradient robustness through super‐linear decay, a principle hypothesized a decade ago, is achieved through autocatalysis. Concentration‐dependent autocatalysis may be a widely used simple feedback to buffer biological activities.</p> </abstract>