Posttranslational modifications in connexins and pannexins

Abstract

Posttranslational modification is a common cellular process that is used by cells to ensure a particular protein function. This can happen in a variety of ways, e.g., from the addition of phosphates or sugar residues to a particular amino acid, ensuring proper protein life cycle and function. In this review, we assess the evidence for ubiquitination, glycosylation, phosphorylation, S-nitrosylation as well as other modifications in connexins and pannexin proteins. Based on the literature, we find that posttranslational modifications are an important component of connexin and pannexin regulation.

Figure 1. Schematic list of post-translations modification throughout the lifespan of connexins and pannexins

Numbers are the amino acids in the proteins as indicated in the references. Note only when amino acids or specific regions on the protein could be identified were they included in the figure, e.g., although palmitoylation has been indicated for Panx2 (Swayne et al., 2010), the exact region on the protein remains unknown. * indicates it was shown indirectly through PKA; # indicates that this cysteine is assumed to be S-nitrosylated in a hemichannel based on (Retamal et al., 2006), but has not been directly shown; + indicates that this data is now in dispute according to work by (Dunn et al., 2012). (1) (Paulson et al., 2000; TenBroek et al., 2001); (2) (Locke et al., 2006); (3) (Cooper & Lampe, 2002); (4) (Cottrell et al., 2003; Kanemitsu et al., 1998; Lampe et al., 1998; Norris et al., 2008; Warn-Cramer et al., 1998); (5) (Doble et al., 2004; Ek-Vitorin et al., 2006; Lampe et al., 2000); (6) (Solan & Lampe, 2008); (7) (Straub et al., 2011); (8) (Kjenseth et al., 2012); (9) (Bao et al., 2007; Bao et al., 2004b); (10) (Toyofuku et al., 2001); (11) (Retamal et al., 2009); (12) (Lampe et al., 2000; Solan et al., 2003); (13) (Kanemitsu et al., 1998; Lampe et al., 1998; Xie et al., 1997); (14) (Beardslee et al., 2000; Solan et al., 2007); (15) (Hertlein et al., 1998); (16) (Yin, Gu & Jiang, 2001; Yin, Liu & Jiang, 2008); (17) (Wagner et al., 2011); (18) (Boassa et al., 2007; Penuela et al., 2007); (19) (Penuela et al., 2007); (20) (Chekeni et al., 2010); (21) (Kim et al., 2011).