LRRTM3 is Dispensable for Amyloid-β Production in Mice

Neuronal LRRTM3 (leucine-rich repeat transmembrane 3) protein has been reported to promote amyloid-beta protein precursor (A beta PP) processing and LRRTM3 is a candidate gene in late-onset Alzheimer's disease. To address the role of LRRTM3 in A beta PP processing and amyloid-beta (A beta) production in vivo, we analyzed amyloidogenic processing of A beta PP in the brains of LRRTM3-deficient mice and transgenic A beta PP/PS1 mice with or without LRRTM3. We did not find differences between the genotypes in the levels of A beta or A beta PP C-terminal fragments indicating that LRRTM3 is not an essential regulator of A beta production in adult mice. Moreover, A beta levels in primary cortical neurons were similar between the genotypes, indicating that LRRTM3 is not required for A beta generation in developing mice.