RESUMEN
The generation of distinct cell fates during development depends on asymmetric cell division of progenitor cells. In the central and peripheral nervous system of Drosophila, progenitor cells respectively called neuroblasts or sensory organ precursors use PAR polarity during mitosis to control cell fate determination in their daughter cells. How polarity and the cell cycle are coupled, and how the cell cycle machinery regulates PAR protein function and cell fate determination is poorly understood. Here, we generate an analog sensitive allele of CDK1 and reveal that its partial inhibition weakens but does not abolish apical polarity in embryonic and larval neuroblasts and leads to defects in polarisation of fate determinants. We describe a novel in vivo phosphorylation of Bazooka, the Drosophila homolog of PAR-3, on Serine180, a consensus CDK phosphorylation site. In some tissular contexts, phosphorylation of Serine180 occurs in asymmetrically dividing cells but not in their symmetrically dividing neighbours. In neuroblasts, Serine180 phosphomutants disrupt the timing of basal polarisation. Serine180 phosphomutants also affect the specification and binary cell fate determination of sensory organ precursors as well as Baz localisation during their asymmetric cell divisions. Finally, we show that CDK1 phosphorylates Serine-S180 and an equivalent Serine on human PAR-3 in vitro.
Asunto(s)
Proteína Quinasa CDC2 , Polaridad Celular , Proteínas de Drosophila , Animales , Fosforilación , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteína Quinasa CDC2/metabolismo , Proteína Quinasa CDC2/genética , Drosophila melanogaster/metabolismo , Drosophila melanogaster/genética , Células-Madre Neurales/metabolismo , Células-Madre Neurales/citología , Órganos de los Sentidos/metabolismo , Órganos de los Sentidos/embriología , Péptidos y Proteínas de Señalización IntracelularRESUMEN
English-speakers sometimes say that they feel "moved to tears," "emotionally touched," "stirred," or that something "warmed their heart;" other languages use similar passive contact metaphors to refer to an affective state. The authors propose and measure the concept of kama muta to understand experiences often given these and other labels. Do the same experiences evoke the same kama muta emotion across nations and languages? They conducted studies in 19 different countries, 5 continents, 15 languages, with a total of 3,542 participants. They tested the construct while validating a comprehensive scale to measure the appraisals, valence, bodily sensations, motivation, and lexical labels posited to characterize kama muta. The results are congruent with theory and previous findings showing that kama muta is a distinct positive social relational emotion that is evoked by experiencing or observing a sudden intensification of communal sharing. It is commonly accompanied by a warm feeling in the chest, moist eyes or tears, chills or piloerection, feeling choked up or having a lump in the throat, buoyancy, and exhilaration. It motivates affective devotion and moral commitment to communal sharing. Although the authors observed some variations across cultures, these 5 facets of kama muta are highly correlated in every sample, supporting the validity of the construct and the measure. (PsycINFO Database Record (c) 2019 APA, all rights reserved).