CCDC134

Molecular adapter required to prevent protein hyperglycosylation of HSP90B1: during translation, associates with nascent HSP90B1 and the STT3A catalytic component of the OST-A complex and tethers them to a specialized translocon that forms a microenvironment for HSP90B1 folding. In the CCDC134-containing translocon, STT3A associates with the SRT pseudosubstrate motif of HSP90B1, preventing access to facultative glycosylation sites until folding is completed, preventing hyperglycosylation and subsequent degradation of HSP90B1. In extracellular secreted form, promotes proliferation and activation of CD8(+) T-cells, suggesting a cytokine-like function. May inhibit ERK and JNK signaling activity. May suppress cell migration and invasion activity, via its effects on ERK and JNK signaling. May also localize in the nucleus: enhances stability of the PCAF histone acetyltransferase (HAT) complex member TADA2A and thus promotes PCAF-mediated histone acetyltransferase activity. Has a critical role in the regulation of osteogenesis and bone development..

Function from UniProtKB (Q9H6E4), read 2026-09-23. CC BY 4.0.