human multiple myeloma tumor

Transcription factor that plays an important role in cellular development and cell survival. Recognizes and binds to the DNA sequence 5'-GCG(T/G)GGGCG-3'. Regulates the expression of numerous target genes, including EPO. Plays an essential role for development of the urogenital system. It has a tumor suppressor as well as an oncogenic role in tumor formation. Function may be isoform-specific: isoforms lacking the KTS motif may act as transcription factors. Isoforms containing the KTS motif may bind mRNA and play a role in mRNA metabolism or splicing. Isoform 1 has lower affinity for DNA, and can bind RNA.

G protein-coupled receptor kinase 6, also known as G protein-coupled receptor kinase GRK6, GRK6, and GPRK6, is a lipid-anchor protein that belongs to the protein kinase superfamily, AGC Ser/Thr protein kinase family, and GPRK subfamily. GRK6 / GPRK6 contains one AGC-kinase C-terminal domain, one protein kinase domain, and one RGS domain. This protein phosphorylates the activated forms of G protein-coupled receptors thus initiating their deactivation. Several transcript variants encoding different isoforms have been described. GRK6 / GPRK6 is widely expressed. GRK6 / GPRK6 silencing causes suppression of signal transducer and activator of transcription 3 (STAT3) phosphorylation associated with a reduction in MCL1 levels and phosphorylation, illustrating a potent mechanism for the cytotoxicity of GRK6 inhibition in multiple myeloma (MM) tumor cells. GRK6 also appears to be involved in responses to morphine. Inhibition of GRK6 represents a uniquely targeted novel therapeutic strategy in human multiple myeloma.