Cajal bodies and their role in plant stress and disease responses

Abstract

Cajal bodies (CBs) are distinct sub-nuclear structures that are present in eukaryotic living cells and are often associated with the nucleolus. CBs play important roles in RNA metabolism and formation of RNPs involved in transcription, splicing, ribosome biogenesis, and telomere maintenance. Besides these primary roles, CBs appear to be involved in additional functions that may not be directly related to RNA metabolism and RNP biogenesis. In this review, we assess possible roles of plant CBs in RNA regulatory pathways such as nonsense-mediated mRNA decay and RNA silencing. We also summarize recent progress and discuss new non-canonical functions of plant CBs in responses to stress and disease. It is hypothesized that CBs can regulate these responses via their interaction with poly(ADP ribose)polymerase (PARP), which is known to play an important role in various physiological processes including responses to biotic and abiotic stresses. It is suggested that CBs and their components modify PARP activities and functions.

Interaction of a plant virus protein with the signature Cajal body protein coilin facilitates salicylic acid‐mediated plant defence responses

“…There is a high degree of cross-kingdom functional conservation of subnuclear bodies. Both the nucleolus and CBs have been implicated in responses to a wide range of biotic and abiotic stresses (Boulon et al, 2010;Bassett, 2012;Love et al, 2017;Makarova et al, 2018). It will be of substantial interest to discover the extent to which coilin operates as a mediator for sensing and triggering of defence against these stresses in plants and other eukaryotic systems.…”

“…spliceosomal small nuclear RNPs, small nucleolar RNPs, telomerase and U7 snRNP) (for reviews see Gall, 2000;Carmo-Fonseca, 2002;Ogg & Lamond, 2002;Cioce & Lamond, 2005;Bassett, 2012). In addition to these well-recognized roles in RNA metabolism and RNA-protein assembly, a growing body of evidence indicates that the nucleolus and CBs also are involved in many other important cell functions such as cell cycle, growth, development and stress responses (Boulon et al, 2010;Bassett, 2012;Love et al, 2017;Kalinina et al, 2018). Thus, the nucleolus and CBs have emerged as multifunctional regulatory subnuclear domains, the roles of which in various biological processes we are just beginning to elucidate.…”

“…Several lines of evidence indicate that animal and plant virus proteins interact with the nucleolus to divert host nucleolar proteins from their natural functions in order to play novel role(s) in the virus infection cycle (Hiscox, 2007;Greco, 2009;Rajam€ aki & Valkonen, 2009;Taliansky et al, 2010;Wright et al, 2010;Semashko et al, 2012;Love et al, 2017;Kalinina et al, 2018). For example, the ability of the umbravirus groundnut rosette virus ORF3 protein to transport viral RNA long distances through the phloem, has been shown to depend strictly on its trafficking through the nucleolus and interaction with fibrillarin, the major nucleolar protein (Kim et al, 2007a,b;Canetta et al, 2008).…”

Resistance to viruses of potato: current status and prospects

“…Основная роль ТК заключается в метаболизме РНК и формиро вании рибонуклеопротеидных частиц, участвующих в транскрипции, сплайсинге и биогенезе рибосом. Глав ным структурным (маркерным) белком ТК, абсолютно необходимым для их сборки, является коилин (Love et al, 2016). Для того чтобы понять роль ТК в заражении растений вирусами, были получены трансгенные растения Nicotiana с нокдауном (knockdawn) гена коилина (ТРkd), что позволило показать, что этот ядерный белок влияет на ответ растения на вирусную инфекцию, но различно для представителей разных таксономических групп вирусов (Shaw et al, 2014).…”

“…По скольку коилин/фибрилларин вовлечены в устойчивость/ восприимчивость растений к различным вирусам и даже абиотическим факторам (Love et al, 2016), очевидно, что эти ядерные белки являются компонентами сигнального пути/путей, обеспечивающих общие защитные механизмы растения. Таким образом, клеточное ядро -центральный узел координации ответов на биотические и абиотические стрессы.…”