Subunit positional effects revealed by novel heteromeric inwardly rectifying K+ channels.

Research Article17 June 1996free access Subunit positional effects revealed by novel heteromeric inwardly rectifying K+ channels. M. Pessia M. Pessia Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author S. J. Tucker S. J. Tucker Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author K. Lee K. Lee Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author C. T. Bond C. T. Bond Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author J. P. Adelman J. P. Adelman Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author M. Pessia M. Pessia Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author S. J. Tucker S. J. Tucker Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author K. Lee K. Lee Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author C. T. Bond C. T. Bond Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author J. P. Adelman J. P. Adelman Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. Search for more papers by this author Author Information M. Pessia1, S. J. Tucker1, K. Lee1, C. T. Bond1 and J. P. Adelman1 1Vollum Institute, Oregon Health Sciences University, Portland, OR 97201, USA. The EMBO Journal (1996)15:2980-2987https://doi.org/10.1002/j.1460-2075.1996.tb00661.x PDFDownload PDF of article text and main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info Kir 4.1 is an inward rectifier potassium channel subunit isolated from rat brain which forms homomeric channels when expressed in Xenopus oocytes; Kir 5.1 is a structurally related subunit which does not. Co-injection of mRNAs encoding Kir 4.1 and Kir 5.1 resulted in potassium currents that (i) were much larger than those seen from expression of Kir 4.1 alone, (ii) increased rather than decreased during several seconds at strongly negative potentials and (iii) had an underlying unitary conductance of 43 pS rather than the 12 pS seen with Kir 4.1 alone. In contrast, the properties of Kir 1.1, 2.1, 2.3, 3.1, 3.2 or 3.4 were not altered by coexpression with Kir 5.1. Expression of a concatenated cDNA encoding two or four linked subunits produced currents with the properties of co-expressed Kir 4.1 and Kir 5.1 when the subunits were connected 4-5 or 4-5-4-5, but not when they were connected 4-4-5-5. The results indicate that Kir 5.1 associates specifically with Kir 4.1 to form heteromeric channels, and suggest that they do so normally in the subunit order 4-5-4-5. Further, the relative order of subunits within the channel contributes to their functional properties. Previous ArticleNext Article Volume 15Issue 121 June 1996In this issue RelatedDetailsLoading ...