World Library  
Flag as Inappropriate
Email this Article

Effector (biology)

Article Id: WHEBN0000542725
Reproduction Date:

Title: Effector (biology)  
Author: World Heritage Encyclopedia
Language: English
Publisher: World Heritage Encyclopedia

Effector (biology)

In biochemistry, an effector molecule is usually a small molecule that selectively binds to a protein and regulates its biological activity. In this manner, effector molecules act as ligands that can increase or decrease enzyme activity, gene expression, or cell signalling. Effector molecules can also directly regulate the activity of some mRNA molecules (riboswitches).

In some cases, proteins can be considered to function as effector molecules, especially in cellular signal transduction cascades.

The term effector is used in other fields of biology. For instance, the effector end of a neuron is the terminus where an axon makes contact with the muscle or organ that it stimulates or suppresses.

Examples for effectors

Allosteric effectors can bind to regulatory proteins involved in RNA transcription in order to change its activity.[1] In this way activator proteins become active to bind to the DNA to promote RNA Polymerase and repressor proteins become inactive and RNA polymerase can bind to the DNA.

Bacterial effectors are injected by bacterial cells, usually pathogens, into the cells of their host. The injection is mediated by specialized secretion systems, e.g. the type III secretion system (TTSS or T3SS).[2]

Fungal effectors are secreted by pathogenic fungi into and around host cells by invasive hyphae to disable defense components and facilitate colonization. Protein secretion systems in fungi involve the Spitzenkörper.[3]

Plant pathogenic fungi use two distinct effector secretion systems[4] and each secretory pathway is specific to an effector family :

  • apoplastic effectors : proteins which stay into the apoplast, they are translocated and accumulated into a distinct compartment enclosing the growing hypha named the EIHM (extra-invasive hyphal membrane).
  • cytoplasmic effectors : proteins which enter the host cytoplasm, they are accumulated into a complex plant-derived structure named the biotrophic interfacial complex (BIC) and they are later translocated across the EIHM inside the plant cell. It has been shown that cytoplasmic effectors can move through a few layers of plant cells, probably a way to prepare them for hyphal invasion.

Types of effectors


  1. ^ Introduction to genetic analysis (10. ed. ed.). New York, NY: Freeman. pp. 410–411.  
  2. ^ Cambronne, E. D.; Roy, C. R. (2006). "Recognition and Delivery of Effector Proteins into Eukaryotic Cells by Bacterial Secretion Systems". Traffic 7 (8): 929–939.  
  3. ^ Steinberg, G. (2007). "Hyphal growth: a tale of motors, lipids, and the spitzenkörper". Eukaryotic Cell 6 (3): 351–360.  
  4. ^ Giraldo MC, Dagdas YF, Gupta YK, Mentlak TA, Yi M, Martinez-Rocha AL, Saitoh H, Terauchi R, Talbot NJ & Valent B (2013). "Two distinct secretion systems facilitate tissue invasion by the rice blast fungus Magnaporthe oryzae" 4. Nat Commun.  

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.