Leucine-rich Repeat Transmembrane Protein 4, Recombinant Human (LRRTM4)

LRRTM4 (Leucinerich repeat transmembrane protein 4) is a member of the LRRTM family of molecules. All LRRTMs are type I transmembrane proteins that contain multiple leucine rich repeats, one PDZ consensus cytoplasmic binding domain, and show expression somewhere in the central nervous system. The LRRTM family is iterated across vertebrate (but not invertebrate) species. Human LRRTM4 is synthesized as a 590 amino acid (aa) precursor that contains a 30aa signal sequence plus a 560aa mature region. The mature molecule contains a 394aa extracellular domain (aa31-424), a 21aa transmembrane segment, and a 105 aa cytoplasmic region. The extracellular domain is characterized by the presence of ten Leurich repeats, flanked by two cysteinerich flanking sequences. Based on other LRRTMs, eukaryotic expression of LRRTM4 will likely yield an 82-86kD glycosylated molecule. There are at least two splice variants. Both show a Val substitution for aa518-590, one of, which is also coupled to an alternative start site at Met312. Mature human LRRTM4 is 95% aa identical to mouse LRRTM4. LRRTM4 is widely expressed, occurring in embryonic distal limb bud mesenchyme plus anterior sclerotome, and in adult testis, lung, muscle and prostate. All LRRTMs are also found in brain. LRRTM4 has been identified in adult granular and mitral neurons of the olfactory bulb, neurons of cerebral cortex layers 2, 4, 5 and 6, and on neurons of the dentate gyrus. Functionally, it appears that LRRTM4 is involved in both preand postsynaptic modeling. Although embedded in the postsynaptic membrane, LRRTM4, seems to induce excitatory/glutamatergic presynaptic differentiation. Postsynaptically, LRRTM4 likely facilitates excitatory synapse formation on dendrites, acting in conjunction with multiple ligandreceptor combinations. In particular, the NR1 NMDA subunit has been shown to coalesce, or aggregate, in regions that experience LRRTM4 clustering. Source: Recombinant protein corresponding to Gln31-Lys424 from human LRRTM4, C-terminal, 6-His tag, expressed in NSO cells (Q86VH4). Biological Activity: Measured by its binding ability in a functional ELISA. When recombinant, human LRRTM4 is coated at 5ug/ml (100ul/well), recombinant human Neurexin 1B/Fc Chimera binds with an apparent KD<15nM., , Storage and Stability:, Lyophilized powder may be stored at -20°C. Stable for 12 months after receipt at -20°C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.