This entry represent GRIP2. In mice GRIP2 functions downstream of Notch3/RBP-Jkappa to regulate myogenic tone in the brain arteries []. In Xenopus GRIP2 is involved in primordial germ cell development and migration []. Glutamate receptor-interacting proteins (GRIPs) are multi-PDZ domain scaffolding proteins required for dendrite development. There are two members of the GRIP family: GRIP1 and GRIP2/ABP (AMPA receptor binding protein) []. GRIPs regulate AMPAR receptor trafficking and neuronal plasticity [, ]. They also bind various receptor and signalling proteins, such as EphB receptors, ephrinB ligands, the proteoglycan NG2, the Fraser syndrome protein Fras1, and matrix metalloproteinase 5 [].
GRIP1-associated protein 1 (GRIPAP1, also known as GRASP-1) is expressed in the CNS and interacts with GRIP1, GRIP2 and AMPA receptors []. It may regulate neuronal ras signaling and contribute to the regulation of AMPA receptor distribution by NMDA receptor activity [].
The microtubule organizing centres (MTOCs) of eukaryotic cells are the sites of nucleation of microtubules, and are known as the centrosome in animal cells and the spindle pole body in yeast. Gamma-tubulin, which is 30% identical to alpha and beta tubulins that form microtubules, appears to be a key protein involved in nucleation of microtubules.Gamma tubulin can assemble into complexes of various sizes with members of the GCP family. In budding yeast, the gamma tubulin-containing small complex (gammaTuSC) contains gamma tubulin, GCP2 and GCP3 (also known as Spc97 and Spc98). In Drosophila and vertebrates, gamma tubulin forms much larger assemblies, termed gamma-tubulin ring complexes (gammaTuRCs), with gamma tubulin, GCP2, GCP3, GCP4, GCP5 and GCP6. The purified gammaTuSC and gammaTuRC complexes exhibit a 'lock washer' shape []. However, the purified gammaTuSC has been shown to have a much lower microtubule-nucleating activity than intact gammaTuRC []. Several models have been proposed to explain their assembly and nucleation mechanism []. This entry represents the GCP family, whose members include GCP2/3/4/5/6 and Spc97/98 []. They contain the GRIP1 and GRIP2 motifs, which are predicted to participate in protein-protein interactions []. They are gamma tubulin binding proteins that have similar protein structures [].
