J Biol Chem. 2003 Apr 25;278(17):14762-8. Epub 2003 Feb 13.
Tamalin is a scaffold protein that interacts with multiple neuronal proteins in distinct modes of protein-protein association.- Official Symbol
- TAMALIN
- Official Full Name
- trafficking regulator and scaffold protein tamalin
- Also known as
- GRASP
- Summary
- This gene encodes a protein that functions as a molecular scaffold, linking receptors, including group 1 metabotropic glutamate receptors, to neuronal proteins. The encoded protein contains conserved domains, including a leucine zipper sequence, PDZ domain and a C-terminal PDZ-binding motif. Alternately spliced transcript variants have been observed for this gene.[provided by RefSeq, Dec 2012]
- Expression
- Broad expression in bone marrow (RPKM 8.3), fat (RPKM 7.8) and 23 other tissues See more
- Orthologs
-
mouse
all
- Preferred Names
- general receptor for phosphoinositides 1-associated scaffold protein
- Names
- GRP1 (general receptor for phosphoinositides 1)-associated scaffold protein
- general receptor for phosphoinositides 1 associated scaffold protein
-
NM_001271856.2 → NP_001258785.1 general receptor for phosphoinositides 1-associated scaffold protein isoform 2
See identical proteins and their annotated locations for NP_001258785.1
Status: REVIEWED- Description
- Transcript Variant: This variant (2) has multiple differences, compared to variant 1. These differences result in a distinct 5' UTR and cause translation initiation at a downstream start codon, compared to variant 1. The encoded protein (isoform 2) is shorter than isoform 1.
- Conserved Domains (1) summary
-
- cd00992
Location:9 → 42 - PDZ_signaling; PDZ domain found in a variety of Eumetazoan signaling molecules, often in tandem arrangements. May be responsible for specific protein-protein interactions, as most PDZ domains bind C-terminal polypeptides, and binding to internal (non-C-terminal) polypeptides and even to lipids has been demonstrated. In this subfamily of PDZ domains an N-terminal beta-strand forms the peptide-binding groove base, a circular permutation with respect to PDZ domains found in proteases.
- cd00992
- Myristoylation restricts orientation of the GRASP domain on membranes and promotes membrane tethering. Heinrich F, et al. J Biol Chem, 2014 Apr 4. PMID 24505136, Free PMC Article
- The scaffolding protein GRASP/Tamalin directly binds to Dock180 as well as to cytohesins facilitating GTPase crosstalk in epithelial cell migration. Attar MA, et al. BMC Cell Biol, 2013 Feb 26. PMID 23441967, Free PMC Article
-
Grp1-associated
scaffold protein (GRASP) is a regulator of the ADP ribosylation factor 6
(Arf6)-dependent membrane trafficking pathway.
Venkataraman A, et al. Cell Biol Int, 2012. PMID 22931251, Free PMC Article AbstractGRASP interacts with Grp1 (general receptor for phosphoinositides 1; cytohesin 3), which catalyses nucleotide exchange on and activation of Arf6 (ADP-ribosylation factor-6). Arf6 is a low-molecular-mass GTPase that regulates key aspects of endocytic recycling pathways. Overexpressed GRASP accumulated in the juxtanuclear ERC (endocytic recycling compartment). GRASP co-localized with a constitutively inactive mutant of Arf6 in the ERC such that it was reversed by expression of wild-type Grp1. Co-expression of GRASP and Grp1 promoted membrane ruffling, a cellular hallmark of Arf6 activation. GRASP accumulation in ERC was found to block recycling of the MHC-I (major histocompatibility complex-I), which is trafficked by the Arf6-dependent pathway. In contrast, overexpression of GRASP had no effect on the recycling of transferrin receptors, which are trafficked by a clathrin-dependent pathway. The findings suggest that GRASP regulates the non-clathrin/Arf6-dependent, plasma membrane recycling and signalling pathways.
- Metabotropic glutamate receptor 5, and its trafficking molecules Norbin and Tamalin, are increased in the CA1 hippocampal region of subjects with schizophrenia. Matosin N, et al. Schizophr Res, 2015 Aug. PMID 26048293
- PDZ-scaffold protein, Tamalin promotes dendritic outgrowth and arborization in rat hippocampal neuron. Mo J, et al. Biochem Biophys Res Commun, 2012 Jun 1. PMID 22569042
- Schizophrenia subjects compared to controls showed a marked increase in CA1 hippocampal Norbin, and Tamalin proteins (47% and 34% respectively), which are endogenous regulators of mGluR5 signalling and trafficking
- myristoylated GRASP promoted tethering and exhibited a unique membrane complex. Thus, myristoylation restricts the membrane orientation of the GRASP domain favoring interactions in trans for membrane tethering.
- GRASP bridges the guanine nucleotide exchange factors (GEFs) that activate Arf and Rac, thereby promoting Arf-to-Rac signaling By binding to both cytohesin 2/ARNO and Dock180.
- GRASP regulates the non-clathrin/Arf6-dependent, plasma membrane recycling and signalling pathways.
- the structural basis of the phosphoinhibition of GRASP-mediated membrane tethering and provide a mechanism for its allosteric regulation.
- protein-protein interaction mediated by ARNO coiled-coil domain required for ARNO induced motility; coiled-coil domain promotes assembly of multiprotein complex containing ARNO and Dock180; assembly of complex requires coiled-coil domain, GRASP and IPCEF
- The crystal structures of the autoinhibitory PDZ domain of Tamalin has implications for the regulation of metabotropic glutamate receptor trafficking.
