Two-hybrid screening

Overview of two-hybrid assay, checking for interactions between two proteins, called here Bait and Prey.
A. The Gal4 transcription factor gene produces a two-domain protein (BD and AD) essential for transcription of the reporter gene (LacZ).
B,C. Two fusion proteins are prepared: Gal4BD+Bait and Gal4AD+Prey. Neither of them are usually sufficient to initiate transcription (of the reporter gene) alone.
D. When both fusion proteins are produced and the Bait part of the first fusion protein interacts with the Prey part of the second, transcription of the reporter gene occurs.

Two-hybrid screening (originally known as yeast two-hybrid system or Y2H) is a molecular biology technique used to discover protein–protein interactions (PPIs)[1] and protein–DNA interactions[2][3] by testing for physical interactions (such as binding) between two proteins or a single protein and a DNA molecule, respectively.

The premise behind the test is the activation of downstream reporter gene(s) by the binding of a transcription factor onto an upstream activating sequence (UAS). For two-hybrid screening, the transcription factor is split into two separate fragments, called the DNA-binding domain (DBD or often also abbreviated as BD) and activating domain (AD). The BD is the domain responsible for binding to the UAS and the AD is the domain responsible for the activation of transcription.[1][2] The Y2H is thus a protein-fragment complementation assay.

  1. ^ a b Young KH (February 1998). "Yeast two-hybrid: so many interactions, (in) so little time". Biology of Reproduction. 58 (2): 302–11. doi:10.1095/biolreprod58.2.302. PMID 9475380.
  2. ^ a b Joung JK, Ramm EI, Pabo CO (June 2000). "A bacterial two-hybrid selection system for studying protein-DNA and protein-protein interactions". Proceedings of the National Academy of Sciences of the United States of America. 97 (13): 7382–7. Bibcode:2000PNAS...97.7382J. doi:10.1073/pnas.110149297. PMC 16554. PMID 10852947.
  3. ^ Hurt JA, Thibodeau SA, Hirsh AS, Pabo CO, Joung JK (October 2003). "Highly specific zinc finger proteins obtained by directed domain shuffling and cell-based selection". Proceedings of the National Academy of Sciences of the United States of America. 100 (21): 12271–6. Bibcode:2003PNAS..10012271H. doi:10.1073/pnas.2135381100. PMC 218748. PMID 14527993.