Spotlight – KRS: A cut away from release in exosomes

JCB

KRS: A cut away from release in exosomes

 
Catherine Rabouille

Cancer cells often trigger an inflammatory process, which in some cases may be driven by the presence of lysyl-tRNA synthetase (KRS) in the medium. Kim et al. (2017. J. Cell Biol.https://doi.org/10.1083/jcb.201605118) now demonstrate that cleavage of the KRS by caspase-8 inside cells triggers its interaction with syntenin and its release in inflammatory exosomes.

Aminoacyl-tRNA synthetases (ARSs) are intriguing enzymes. Intracellularly, they catalyze the covalent attachment of amino acids to tRNAs and are key regulators of protein translation. However, these housekeeping enzymes have many other tricks up their sleeves. In the cell, several ARSs are also able to regulate gene expression at the level of transcription, splicing, and translation but via noncatalytic and unique mechanisms. ARSs also have different functions in the extracellular space, where they can elicit cytokine signaling responses that control angiogenesis, induce immune and proinflammatory gene expression programs, and trigger cell migration or apoptosis. The response elicited by particular ARSs is specific to the target cells (Son et al., 2014). For instance, when present in the extracellular medium, lysyl-tRNA synthetase (KRS) binds to macrophages and monocytes and activates MAPK signaling pathways that induce macrophage migration and TNF production (Park et al., 2005). How ARSs are released to the extracellular medium to carry out these activities is unknown. ARSs do not contain a signal peptide, and pharmacological agents blocking secretion through the secretory pathway have no effect on the amount of ARS in the medium. For a while, the presence of ARSs in the extracellular medium was thus thought to be caused by their passive release from cells that have undergone necrosis. In this issue, Kim et al. reinvestigate how KRS is released from cancer cells and find that this occurs through a caspase-8– and syntenin-dependent incorporation of KRS in exosomes.

http://jcb.rupress.org/content/early/2017/06/15/jcb.201706039

Related Post

환자 적어 속도 못내는 치료제 개발
views 76
(동아사이언스=윤신영기자) 2018년 09월 11일 07:03 메르스 바이러스에 감염된 인체세포 국내에서 3년만에 메르스 환자가 발생하며 메르스 치료제에 다시 관심이 쏠리고 있다. 전세계적으로 제품화된 치료약은 아직 전무하지만, 항체를 이용한 일부 후보물질 ...
김희남 고대의대 교수 “항생제 남용하면 고혈압, 당뇨, 아토피에 취약”...
views 57
(조선비즈=허지윤기자) 입력 : 2018.07.18 18:19 고려대학교 의과대학은 김희남(사진) 의과학과 교수가 항생제 남용으로 인한 장내 미생물 불균형이 만성질환을 일으키는 기전을 세계 최초로 제시했다고 18일 밝혔다. 항생제는 세균 감염 치료를 ...
Stocking oncology’s medicine cabinet
views 1349
Stocking oncology's medicine cabinet Paula A. Kiberstis, John Travis Science  17 Mar 2017: Vol. 355, Issue 6...
A paper on a new ARS receptor was published in the...
views 299
Dr. Hyuck Sang Kwon's article was published in the Journal of Cell Science for discovering  a new AIMP1 receptor.   The title of the article...

CONTACT US

We're not around right now. But you can send us an email and we'll get back to you, asap.

Sending

©2010-2018 Medicinal Bioconvergence Research Center. All rights reserved.

Log in with your credentials

Forgot your details?

Skip to toolbar