{"uniprot":"Q9BWQ6","gene":"YIPF2","name":"Protein YIPF2","organism":"Homo sapiens (Human)","status":"dark","length":316,"sequence":"MASADELTFHEFEEATNLLADTPDAATTSRSDQLTPQGHVAVAVGSGGSYGAEDEVEEESDKAALLQEQQQQQQPGFWTFSYYQSFFDVDTSQVLDRIKGSLLPRPGHNFVRHHLRNRPDLYGPFWICATLAFVLAVTGNLTLVLAQRRDPSIHYSPQFHKVTVAGISIYCYAWLVPLALWGFLRWRKGVQERMGPYTFLETVCIYGYSLFVFIPMVVLWLIPVPWLQWLFGALALGLSAAGLVFTLWPVVREDTRLVATVLLSVVVLLHALLAMGCKLYFFQSLPPENVAPPPQITSLPSNIALSPTLPQSLAPS","function_summary":"A multi-pass membrane scaffold at the Golgi that organizes vesicle trafficking between the endoplasmic reticulum and Golgi. It assembles and stabilizes transport machinery across consecutive Golgi compartments and the trans-Golgi network, cycling on and off transport vesicles. By mediating multivalent protein interactions rather than catalysis, it coordinates coat and small GTPase systems to drive ER-to-Golgi cargo flow and intra-Golgi progression.","plain_language":"YIPF2 has barely been studied. The model's best guess: A multi-pass membrane scaffold at the Golgi that organizes vesicle trafficking between the endoplasmic reticulum and Golgi. It assembles and stabilizes transport machinery across consecutive Golgi compartments and the trans-Golgi network, cycling on and off transport vesicles.","uniprot_summary":"Involved in the Golgi apparatus.","go_terms":{"molecular_function":[{"id":"GO:0005515","label":"protein binding"}],"biological_process":[{"id":"GO:0006888","label":"endoplasmic reticulum to Golgi vesicle-mediated transport"}],"cellular_component":[{"id":"GO:0030133","label":"transport vesicle"},{"id":"GO:0005802","label":"trans-Golgi network"},{"id":"GO:0005797","label":"Golgi medial cisterna"},{"id":"GO:0000138","label":"Golgi trans cisterna"}]},"interpro":[{"id":"IPR006977","name":"Yip1 domain","type":"domain","start":102,"end":274},{"id":"IPR039765","name":"Protein Yip5/YIPF1/YIPF2","type":"family","start":26,"end":283}],"reasoning":"I begin with the InterPro architecture. The polypeptide carries IPR006977 (Yip1 domain, residues 102–274), a hallmark membrane-embedded module that defines the Yip1/YIPF family of trafficking factors. This core is encompassed by IPR039765 (Protein Yip5/YIPF1/YIPF2 family, residues 26–283), which specifies a conserved Golgi/ER–Golgi interface cohort that forms oligomeric assemblies. The ordered layout—an N-terminal region feeding into a central Yip1 domain and extending through a family-wide envelope—creates a multi-pass membrane scaffold optimized for assembling and stabilizing trafficking complexes rather than catalyzing chemistry. Such scaffolds operate through multivalent contacts, directly supporting GO:0005515 protein binding as the primary molecular function.\n\nA Yip1-domain scaffold at the Golgi causes vesicle flow by organizing coat/adaptor assemblies and small GTPase cycles that drive ER-to-Golgi and intra-Golgi transport. This architecture is classically coupled to COPII/COPI and Rab/Ypt pathways, which together generate and sort carriers. Consequently, the protein’s activity feeds directly into GO:0006888 endoplasmic reticulum to Golgi vesicle-mediated transport. The same assembly logic explains its steady-state residence across multiple consecutive Golgi compartments—GO:0005797 Golgi medial cisterna and GO:0000138 Golgi trans cisterna—as well as the GO:0005802 trans-Golgi network, where outbound sorting and maturation occur. Its presence in GO:0030133 transport vesicle follows naturally: the Yip1-domain platform is recruited to budding and tethering sites that generate and receive carriers.\n\nThe subcellular location profile—Golgi apparatus membrane and a multi-pass topology—emerges directly from the Yip1/YIPF family signatures. Multi-pass helices anchor the scaffold in the Golgi and ER–Golgi intermediate compartments, positioning cytosolic loops to capture coats and tethers. This membrane-embedded assembly mechanism accounts for the observed distribution across medial/trans cisternae and the trans-Golgi network, and for cycling through transport vesicles.\n\nMechanistically, I hypothesize that the Yip1 domain nucleates a YIPF oligomer that binds small GTPases and coat/tether modules to choreograph vesicle budding and fusion. Likely partners include Rab/Ypt modules and COPII/COPI machinery that define ER–Golgi flux. By stabilizing these complexes, the protein enforces directional cargo flow through the Golgi stack and onward to the trans-Golgi network.","category":"dark","control_evaluation":null,"validation_plan":null,"structure":{"source":"AlphaFold DB","pdb":"/structures/AF-Q9BWQ6.pdb","alphafold":"https://alphafold.ebi.ac.uk/entry/Q9BWQ6"},"links":{"uniprot":"https://www.uniprot.org/uniprotkb/Q9BWQ6/entry","atlas":"/p/Q9BWQ6"},"provenance":{"model":"BioReason-Pro (ESM3 esm3-sm-open-v1)","source_list":"Pharos Tdark","note":"AI prediction, not experimentally verified"}}