LAMTOR2

The LAMTOR2 gene (LAMTOR2 stands for "Late Endosomal/Lysosomal Adaptor, MAPK And MTOR Activator 2") is a protein coding gene located on chromosome 1q22. Several transcript variants encoding different isoforms have been found for this gene.

The encoded protein functions as part of the ragulator complex involved in amino acid recognition and mTORC1 activation. LAMTOR3 (MP1) and LAMTOR2 (p14) form a heterodimer as part of the larger ragulator complex required for MAPK and mTOR1 signaling from late endosomes/lysosomes. Loss of LAMTOR2 (p14) results in an unstable cytosolic monomeric pool of LAMTOR 3). Monomeric cytoplasmic LAMTOR3 is rapidly degraded in a proteasome-dependent but lysosome-independent manner (de Araújo ME et al. 2013).

Endosomes carrying the p14-MP1 (LAMTOR2/3) complex have an essential function in the dynamics of focal adhesions (FAs). p14-MP1-positive endosomes move along microtubules (MTs) to the cell periphery in a kinesin1- and Arl8b-dependent manner. There, they target focal adhesions (FAs) to regulate FA turnover, which is required for cell migration (Schiefermeier N et al. 2014).

In humans, a mutation in this gene is associated with the

• primary immunodeficiency syndrome by Lamtor2 defect.

associated.

1. Bohn G et al. (2007) A novel human primary immunodeficiency syndrome caused by deficiency of endosomal adaptor protein p14. Nature Med 13: 38-45.
2. de Araújo ME et al (2013) Stability of the endosomal scaffold protein LAMTOR3 depends on heterodimer assembly and proteasomal degradation. J Biol Chem 288:18228-18242.
3. Schiefermeier N et al (2014) The late endosomal p14-MP1 (LAMTOR2/3) complex regulates focal adhesion dynamics during cell migration. J Cell Biol 205:525-540.
4. Zamani R et al (2021) Primary immunodeficiency associated with hypopigmentation: A differential diagnosis approach. Allergol Immunopathol (Madr) 49:178-190.