Hello friends in this lecture we'll be discussing about nuclear transport as we know it's a mechanism that involves transportation of molecules between cytosol and nucleus of the cell in this process we see both entry as well as exit of molecules takes place between cytosol and nucleus of the cell another thing we see here is that it's mediated bya NPCs that's nuclear Poe complexes these are the protein complexes through which micro molecule transport occurs approximately molecules above 5,000 dotons of molecular weight pass through these complex and Below 5,000 doons can pass easily through this membrane without using the energy or anything so they can pass passively another important point to be noted here is that it's by these caropine transport proteins which mediates this process caropine proteins are of two types first is importance and second are exports importance as suggested that means they are able to import protein or any micro molecule which acts as a corgo into the nucleus and exporting are the proteins that are able to transport a protein or any molecule from nucleus into the cytool and importance bind to NLC that's nuclear localization signal and it's amino acid sequence and in most of the case it's positively charged lense and arginines NLC takes for specific prot proteins which are to be transported while as in case of exporting these binds to NES that's nuclear export signal which is amino acid sequence also but these are the hydrophobic ones like leucines and finally the energy for this process is provided by rain gradient That's rated nuclear protein this is the protein which is present within the cell and that's able to provide energy for this process now let's see in detail how this process occurs within the cell we see here the nuclear membrane or nuclear envelope which has got nuclear Poe complexes like these we can see in this figure through which this transport occurs we see here in the cytool we have the protein molecule that acts as a corgo and this cargo is to be transported into the nucleus and for this transportation we have caropine molecules or caropine proteins and in this case we have the importin and this importin will carry the molecule from cytosol into the nucleus important has got two domains Alpha and beta domain Alpha domain binds to NLS that's nuclear localization signal and this analyst will carry the corg or the protein into the nucleus this analyst tags for a specific protein it must be noted here and this complex has ran GDP attached to it which provides energy for this transport and we have the complete complex form here and it gets into the nucleus with the help of this R GDP the important comp comp Lex after getting into the nucleus releases of the protein there's the cargo into the nucleus and the EMP part that's the important and NLS signal is interacted with rang GF that's goni nucleotide exchange Factor where which the GTP is exchanged for GDP and we get the important complex in the form of GTP that means this GDP is exchanged for GTP by this range GF after this we have the M import NLS complex is driving outside of the nucleus with the help of GTP which has got attached to it in the previous step and here in the cytool that ran Gap that's gtps activating protein hydrolyzes GTP to GDP again and releases one phosphate and we get the GTP form of important complex so we see here we are back to the same complex from where the cycle had started and the cycle for export is same but in the reverse Direction and with the nuclear export signal so this was all about nuclear transport hope you like the video give it a thumbs up if you like it and do subscribe to this channel