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).
Functions as a component of the nuclear pore complex (NPC) and the COPII coat (By similarity). At the endoplasmic reticulum, SEC13 is involved in the biogenesis of COPII-coated vesicles (By similarity). Recruited to transcriptionally active chromatin at the time of transcription initiation by RNA polymerase II (PubMed:20144761). Required for proper expression of ecdysone-responsive genes such as Eip74EF and Eip75B during larval development (PubMed:20144761). Required for reactivation of transcription after heat shock (PubMed:20144761). Required for nuclear import of phosphorylated Mad via importin msk (PubMed:20547758). Has no role in classical nuclear localization signal (cNLS)-dependent nuclear import via importin-beta (PubMed:20547758). {By
SimilarityUniProtKB:P55735, Experimental EvidencePubMed:20144761, Experimental EvidencePubMed:20547758}. A component of the GATOR subcomplex GATOR2 which functions as an activator of the amino acid-sensing branch of the TORC1 signaling pathway (PubMed:27166823). The two GATOR subcomplexes, GATOR1 and GATOR2, regulate the TORC1 pathway in order to mediate metabolic homeostasis, female gametogenesis and the response to amino acid limitation and complete starvation (PubMed:27166823). GATOR2 activates the TORC1 signaling pathway through the inhibition of the GATOR1 subcomplex, controlling the switch to cell proliferation and growth under nutrient replete conditions and during female oocyte development (PubMed:27166823). {Experimental EvidencePubMed:27166823}.
National and Kapodistrian University of Athens
Department of Biology
Biophysics & Bioinformatics Laboratory