The nuclear envelope is a membrane system which surrounds the nucleoplasm of eukaryotic cells. It is composed of the nuclear lamina, nuclear pore complexes and two nuclear membranes. The space between the two membranes is called the nuclear intermembrane space.
The nuclear pore complex (NPC) constitutes the exclusive means of nucleocytoplasmic transport. NPCs allow the passive diffusion of ions and small molecules and the active bidirectional transport of macromolecules such as proteins, RNAs etc across the double-membrane nuclear envelope.The NPC is composed of at least 30 distinct subunits known as Nucleoporins (NUPs).
Acts as an adapter protein linking the dynein motor complex to various cargos and converts dynein from a non-processive to a highly processive motor in the presence of dynactin. Facilitates and stabilizes the interaction between dynein and dynactin and activates dynein processivity (the ability to move along a microtubule for a long distance without falling off the track) (By similarity). Facilitates the binding of RAB6A to the Golgi by stabilizing its GTP-bound form. Regulates coat complex coatomer protein I (COPI)-independent Golgi- endoplasmic reticulum transport via its interaction with RAB6A and recruitment of the dynein-dynactin motor complex (PubMed:25962623). Contributes to nuclear and centrosomal positioning prior to mitotic entry through regulation of both dynein and kinesin-1. During G2 phase of the cell cycle, associates with RANBP2 at the nuclear pores and recruits dynein and dynactin to the nuclear envelope to ensure proper positioning of the nucleus relative to centrosomes prior to the onset of mitosis (By similarity). {By
SimilarityUniProtKB:Q921C5, Experimental EvidencePubMed:25962623}.
Spinal muscular atrophy, lower extremity-predominant 2A, childhood onset, autosomal dominant (SMALED2A) [MIM:615290]: An autosomal dominant form of spinal muscular atrophy characterized by early-childhood onset of muscle weakness and atrophy predominantly affecting the proximal and distal muscles of the lower extremity, although some patients may show upper extremity involvement. The disorder results in delayed walking, waddling gait, difficulty walking, and loss of distal reflexes. Some patients may have foot deformities or hyperlordosis, and some show mild upper motor signs, such as spasticity. Sensation, bulbar function, and cognitive function are preserved. The disorder shows very slow progression throughout life. {Experimental EvidencePubMed:23664116, Experimental EvidencePubMed:23664119, Experimental EvidencePubMed:23664120, Experimental EvidencePubMed:28635954}. Note=The disease is caused by variants affecting the gene represented in this entry. Spinal muscular atrophy, lower extremity-predominant, 2B, prenatal onset, autosomal dominant (SMALED2B) [MIM:618291]: An autosomal dominant neuromuscular disorder characterized by decreased fetal movements, fractures in utero, severe congenital joint contractures, arthrogryposis multiplex congenita, severe hypotonia, muscle atrophy, and respiratory insufficiency and failure due to muscle weakness. Some patients may have dysmorphic facial features and/or abnormalities on brain imaging. Death in early childhood may occur. {Experimental EvidencePubMed:27751653, Experimental EvidencePubMed:28635954, ECO:0000269|PubMed:30054298}. Note=The disease is caused by variants affecting the gene represented in this entry.
E3 ubiquitin-protein ligase LNX (EC 2.3.2.27) (Ligand of Numb-protein X 1) (Numb-binding protein 1) (PDZ domain-containing RING finger protein 2) (RING-type E3 ubiquitin transferase LNX)
National and Kapodistrian University of Athens
Department of Biology
Biophysics & Bioinformatics Laboratory