Can Interference of GIP activity modulate GPCRs for therapeutic gains?

Kenneth Chinkwo, I.M. Coupar, E. Sloan, N. Chetty, H.R. Irving

Research output: Other contribution to conferenceAbstractpeer-review


Introduction: GPCRs are a large family of cell surface proteins participating in signal transduction where the C-terminus recruits GPCR Interacting Proteins (GIPs) that regulate GPCR function. The 5-HT4 (a, d, e, f and g) receptor splice variants possess canonical type 1 or type 2 PDZ domains predicted to interact with various GIPs which could influence their modulatory and prokinetic functions in the intestine (Coupar et al. 2007).Aims: To investigate the distribution of 5-HT4 receptors and GIPs in the guinea pig intestine and secondly to determine if human 5-HT4 receptors and specific GIPs interact using an in vitro cell system.Methods: RT-PCR, western and immunoflourescence analysis were used to investigate transcript and protein expression. N-terminal FLAG tagged 5-HT4 receptor splice variants and Lin 7 homologues (or Veli) with C-terminal tagged V5, c-Myc and HA constructs were generated and expressed in COS-7 cells to study protein interactions.Results: 5-HT4 receptors, GRKs and Lin 7 homologues were expressed in the guinea pig intestine. Lin 7 homologues and 5-HT4 receptors co-localized in cell lines and the 5-HT4a receptor and Lin 7 were co-immunoprecipitated.Discussion: We have previously shown that 5-HT4 receptors and the GIPs, GRKs and Lin7 homologues, are found in the human colon (Chetty et al. 2009). Our data here indicates that this also occurs in the guinea pig and we demonstrate that it may be possible for 5-HT4 receptor and Lin 7 to interact in the same cells. The results suggest that Lin 7 (Veli) could be a potential target to modulate 5-HT4 receptor function. This would be of particular relevance when 5-HT4 splice variant expression is altered as occurs in cancerous tissue (Cartier et al. 2005).
Original languageEnglish
Number of pages1
Publication statusPublished - 2014
EventComBio2014 - National Convention Centre, Canberra, Australia
Duration: 28 Sept 201402 Oct 2014 (program)


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