Caprin1/MiR-16

Accession #/Synonyms: NP_976240;Mir-16; Cytoplasmic cell cycle associated protein1, GPI anchor membrane protein 1, Membrane component chromosome 11 marker protein 1.  

Cytoplasmic activation and proliferation-associated protein 1 (caprin1) is a ubiquitously expressed cytoplasmic phosphor-protein that is required for normal progression through the G1/Gs phase of the cell cycle and is abundantly present in the post synaptic granules in the dendrites of neurons. There are at least two subtypes of Caprin identified (Caprin 1 and Caprin 2). Caprin-1 exhibits a highly conserved motif, F(M/I/L)Q(D/E)Sx(I/L)D that binds to the NTF-2-like domain of G3BP-1. The carboxy-terminal region of Caprin-1 selectively bound mRNA for c-Myc or cyclin D2, this binding being diminished by mutation of the three RGG motifs and abolished by deletion of the RGG-rich region (1).  Over expression of Caprin 1 induced the production of cytoplasmic stress granules,  and cuased phosphorylation of eukaryotic translation initiation factor eIF-2alfa (eIF2a) via mechanism that depends upon the binding to mRNA resulting in global inhibition in protein synthesis (1). 

Expression of Caprin 1 correlates with the frequency of cell differentiation, however, it is also expressed at high levels in adult brain (2).  Although Caprin-1 was initially mischaracterized as a p137 glycosylphosphatidylinositol-anchored membrane protein (10), it does not occur on the plasma membrane and the current names for the locus, M11S1 (for membrane component, chromosome 11, surface marker 1) or Gpiap1 (glycosylphosphatidylinositol-anchored membrane protein 1), are misleading.  Caprin 1has two homologues region (HR) domains HR1 and HR2 which are also present in Caprin 2. The HR2 domains in both carpin 1 and 2 exhibit RGG motif that are typical for RNA binding protein. IN brain Caprin 1 is present in messenger ribonucleoproiten particles (mRNPs) that also contain other RNA binding proteins like hnRNPK, PABP, alphfa and beta-tubulin, and motor protein dynein (3). Caprin 1/miR-16 also regulate the expression of serotonin transporter (SERT) expression and therefore could be a therapeutic target for antidepressant drugs (4).     

Caprin 1- selective antibodies were generated against peptides form unique region on Caprin 1 protein from within the region surrounding aa 200-250 of Caprin 1.  This region was not only antigenic but also lies on the surface of the protein in native or in partially denatured Caprin 1 confirmation.  The anti-Caprin 1-selective antibodies are fully characterized for applications in western blotting and ELISA at the recommended dilutions.  The Caprin 1antibodies are affinity purified on an immobilized antigen based affinity matrix, the isolated antibodies were then stabilized in antibody stabilization buffer for long-term storage.  FabGennix Int. Inc. provides Caprin 1Western blot positive control samples in “ready-to-use” SDS-PAGE sample buffer.  Limited quantities of antigenic blocking peptide for Caprin 1antibody is also available, please inquire before ordering.  FabGennix Int. Inc., will also conjugate this antibody to fluorophores and other secondary enzymes at a nominal price. FabGennix also provides custom antibody production services for researchers that are looking for high affinity mono and polyclonal antibodies in various species. We specialize in making application specific antibodies that are useful in IHC, confocal and other applications where native antigen is detected. For a complete listing of all FabGennix antibodies please visit www.Fabgennix.com. 

For research use only, not for diagnostic or therapeutic use.