C-jun-amino-terminal kinase-interacting protein 2 is a protein or the name of the gene that encodes it. [5] [6] The gene is also known as Islet-Brain-2 (IB2).
This protein is highly expressed in the brain and is almost always deleted in Phelan-McDermid syndrome (PMS). MAPK8IP2 appears to regulate the ratio of AMPA receptors to NMDA receptors at glutamate synapses, [7] and thus may be an important contributor to the intellectual dysfunction and related neurological manifestations characteristic of PMS.
The protein encoded by this gene is closely related to MAPK8IP1/IB1/JIP-1, a scaffold protein that is involved in the c-Jun amino-terminal kinase signaling pathway. This protein is expressed in brain and pancreatic cells. It has been shown to interact with, and regulate the activity of MAPK8/JNK1, and MAP2K7/MKK7 kinases. This protein thus is thought to function as a regulator of signal transduction by protein kinase cascade in brain and pancreatic beta-cells. Alternatively spliced transcript variants encoding distinct isoforms have been reported for this gene. [6]
MAPK8IP2 has been shown to interact with MAP3K10, [5] Mitogen-activated protein kinase 9, [5] LRP2, [8] [9] LRP1, [8] MAPK8IP3, [10] MAP3K12, [5] MAPK8IP1, [5] MAP2K7 [5] [11] and MAP3K11. [5]