Guanine nucleotide exchange factor (GEF) which activates RAB21 and possibly RAB28 (PubMed:20937701, PubMed:25648148). Promotes the exchange of GDP to GTP, converting inactive GDP-bound Rab proteins into their active GTP-bound form (PubMed:20937701, PubMed:25648148). In response to starvation-induced autophagy, activates RAB21 which in turn binds to and regulates SNARE protein VAMP8 endolysosomal transport required for SNARE-mediated autophagosome-lysosome fusion (PubMed:25648148). Acts as an adapter for the phosphatase MTMR2 (By similarity). Increases MTMR2 catalytic activity towards phosphatidylinositol 3,5-bisphosphate and to a lesser extent towards phosphatidylinositol 3-phosphate (By similarity). {By
SimilarityUniProtKB:E9PXF8, Experimental EvidencePubMed:20937701, Experimental EvidencePubMed:25648148}.
Charcot-Marie-Tooth disease 4B2 (CMT4B2) [MIM:604563]: A recessive demyelinating form of Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, characterized by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal muscles of the arms. Charcot-Marie-Tooth disease is classified in two main groups on the basis of electrophysiologic properties and histopathology: primary peripheral demyelinating neuropathies (designated CMT1 when they are dominantly inherited) and primary peripheral axonal neuropathies (CMT2). Demyelinating neuropathies are characterized by severely reduced nerve conduction velocities (less than 38 m/sec), segmental demyelination and remyelination with onion bulb formations on nerve biopsy, slowly progressive distal muscle atrophy and weakness, absent deep tendon reflexes, and hollow feet. By convention autosomal recessive forms of demyelinating Charcot-Marie- Tooth disease are designated CMT4. {Experimental EvidencePubMed:12554688, Experimental EvidencePubMed:12687498, Experimental EvidencePubMed:15304601, Experimental EvidencePubMed:15477569}. Note=The disease is caused by variants affecting the gene represented in this entry.
Thioredoxin domain-containing protein 12 (EC 1.8.4.2) (Endoplasmic reticulum resident protein 18) (ER protein 18) (ERp18) (Endoplasmic reticulum resident protein 19) (ER protein 19) (ERp19) (Thioredoxin-like protein p19) (hTLP19)
National and Kapodistrian University of Athens
Department of Biology
Biophysics & Bioinformatics Laboratory