This coiled-coiled domain, CCDC134, is a secretory protein that inhibits Mitogen activated protein kinase (MAPK) pathways such as Raf-1/MEK/ERK and JNK/SAPK but not p38. CCDC134 is widely expressed in normal adult tissues, tumour tissues and cell lines, which shows its importance in cell signal transduction pathways, transcription regulation and therefore cell survival [1]. Additionally, CCDC134 is known to bind to a transcription adaptor, hADA2a, which forms part of the general control nonderepressible 5 (GCN5) histone acetyltransferase complex. Acetylation usually 'switches genes on' for transcription. Moreover, knocking out CCDC134 suppressed hADA2a-induced cell apoptosis activity and G1/S cell cycle arrest suggesting its importance in cell survival [2]. This family of proteins is found in eukaryotes. Proteins in this family are typically between 188 and 257 amino acids in length. This family is a coiled-coil domain containing protein 134 (CCDC134) whereby the coiled-coiled domain is a ubiquitous motif involved in oligomerisation.

1: CCDC134, a novel secretory protein, inhibits activation of ERK and JNK, but not p38 MAPK. Huang J, Shi T, Ma T, Zhang Y, Ma X, Lu Y, Song Q, Liu W, Ma D, Qiu X; Cell Mol Life Sci. 2008;65:338-349. PMID:18087676

2: CCDC134 interacts with hADA2a and functions as a regulator of hADA2a in acetyltransferase activity, DNA damage-induced apoptosis and cell cycle arrest. Huang J, Zhang L, Liu W, Liao Q, Shi T, Xiao L, Hu F, Qiu X; Histochem Cell Biol. 2012;138:41-55. PMID:22644376