Biology subjects

Watson, J. L.

Publications and source records attributed to Watson, J. L..

3 recordsLinked to original sources

bioRxiv2020

Fibrinogen anchors enable efficient multiplexed patterning of active proteins and subcellular control of membrane-receptor distribution

Protein micropatterning allows proteins to be precisely deposited onto a substrate of choice, and is now routinely used in cell biology and in vitro reconstitution. However, a drawback of current technology is that micropatterning efficiency can be variable between proteins, and that proteins may lose activity on the micropatterns. Here, we describe a general method to enable micropatterning of virtually any protein at high specificity and homogeneity while maintaining its activity. Our method is based on an anchor that micropatterns well, Fibrinogen, which we functionalized to bind to common purification tags. This enhances micropatterning on various substrates, facilitates multiplexed micropatterning, and dramatically improves the on-pattern activity of fragile proteins like molecular motors. Furthermore, it enhances the micropatterning of hard to micropattern cells. Last, this method enables subcellular micropatterning, whereby complex micropatterns simultaneously control cell shape and the distribution of transmembrane receptors within that cell. Altogether, these results open new avenues for cell biology.

cell biology↗

bioRxiv2020

Canine tumor mutation rate is positively correlated with TP53 mutation across cancer types and breeds

Spontaneous canine cancers are a valuable but relatively understudied and underutilized model in cancer research. To enhance their usage, we reanalyzed whole exome sequencing data published for 601 dogs with mammary cancer, osteosarcoma, oral melanoma, lymphoma, glioma or hemangiosarcoma from over 35 breeds, after rigorous quality control, including breed validation. Each cancer type harbors distinct molecular features, with major pathway alterations matching its human counterpart (e.g., PI3K for mammary cancer and p53 for osteosarcoma). On average, mammary cancer and glioma have lower mutation rates (median <0.5 mutation per Mb), whereas oral melanoma, osteosarcoma and hemangiosarcoma have higher mutation rates (median [≥]1 mutation per Mb). Across cancer types and across breeds, the mutation rate is strongly associated with TP53 mutation, but not with PIK3CA mutation. The mutation rate is also associated with a mutation signature enriched in osteosarcoma of Golden Retrievers, independent of TP53 mutation. Finally, compared to other breeds examined, DNA repair genes appear to be less conserved in Golden Retriever which is predisposed to numerous cancers.

cancer biology↗

bioRxiv2020

Compensatory ion transport buffers daily protein rhythms to regulate osmotic balance and cellular physiology

Between 6-20% of the cellular proteome is under circadian control to tune cell function with cycles of environmental change. For cell viability, and to maintain volume within narrow limits, the osmotic pressure exerted by changes in the soluble proteome must be compensated. The mechanisms and consequences underlying compensation are not known. Here, we show in cultured mammalian cells and in vivo that compensation requires electroneutral active transport of Na+, K+, and Cl- through differential activity of SLC12A family cotransporters. In cardiomyocytes ex vivo and in vivo, compensatory ion fluxes alter their electrical activity at different times of the day. Perturbation of soluble protein abundance has commensurate effects on ion composition and cellular function across the circadian cycle. Thus, circadian regulation of the proteome impacts ion homeostasis with substantial consequences for the physiology of electrically active cells such as cardiomyocytes.

cell biology↗