Kozubowski Lukasz, Aboobakar Eanas F, Cardenas Maria E, Heitman Joseph
Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
Eukaryot Cell. 2011 Nov;10(11):1396-402. doi: 10.1128/EC.05087-11. Epub 2011 Jul 1.
Calcineurin is a calcium-calmodulin-activated serine/threonine-specific phosphatase that operates during cellular responses to stress and plays a prominent role in transcriptional control, whereas regulatory events beyond transcription are less well characterized. This study reveals a novel transcription-independent role of calcineurin during the temperature stress response in the human fungal pathogen Cryptococcus neoformans. The diffusely cytoplasmic calcineurin catalytic subunit Cna1 relocates to endoplasmic reticulum (ER)-associated puncta and the mother-bud neck when cells are subjected to 37°C. More than 50% of Cna1 puncta contain the P-body constituent decapping enzyme Dcp1 and the stress granule constituent poly(A)-binding protein Pub1. These results support a model in which calcineurin orchestrates thermal stress responses by associating with sites of mRNA processing.
钙调神经磷酸酶是一种钙调蛋白激活的丝氨酸/苏氨酸特异性磷酸酶，在细胞应激反应中发挥作用，在转录调控中起重要作用，而转录以外的调控事件则较少被明确描述。本研究揭示了钙调神经磷酸酶在人类真菌病原体新型隐球菌温度应激反应中一种新的非转录作用。当细胞暴露于37°C时，弥漫性细胞质中的钙调神经磷酸酶催化亚基Cna1会重新定位到内质网（ER）相关的点状结构以及母-芽颈部。超过50%的Cna1点状结构含有P体成分去帽酶Dcp1和应激颗粒成分聚腺苷酸结合蛋白Pub1。这些结果支持了一种模型，即钙调神经磷酸酶通过与mRNA加工位点结合来协调热应激反应。
