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

More New Cancer Drugs Mean Higher Costs But Also L...
views 276
More New Cancer Drugs Mean Higher Costs But Also Longer Lives by MAGGIE FOX Spending on cancer treatments has spiked past the $1...
백신 개발·DNA 해독… 전염병 막을 ‘국제연합군’ 뭉쳤다...
views 197
백신 개발·DNA 해독… 전염병 막을 '국제연합군' 뭉쳤다 박건형 기자 황승식 서울대 보건대학원 교수 입력 : 2017.06.03 03:02 판데믹에 맞서는 인류 WHO·美·유럽 중심으로 에볼라 백신 개발 성공 빌 게이...
신약 R&BD ‘바이오콘’ 주목…11개 파이프라인...
views 1142
신약 R&BD '바이오콘' 주목...11개 파이프라인 진행 제약바이오기업과 고효율 신약개발 플랫폼 구축-신약 타깃 개발 추진 이권구 기자 | kwon9@yakup.com    기사입력 2016-06-20 06:41     최종수정 2016-06-20 ...
Top Biotech Trends for 2017
views 674
Top Biotech Trends for 2017 What key trends could propel biotech forward in 2017? No doubt about it—2016 was a tumultuous year for biotech. But that...

CONTACT US

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

Sending

©2010-2017 Medicinal Bioconvergence Research Center. All rights reserved.

Log in with your credentials

Forgot your details?

Skip to toolbar