RB — Solanum tuberosum

Summary

PGSC0003DMG400011581, designated RB (also known as RBR, StRBR1, and other synonyms) on potato chromosome 9, encodes a retinoblastoma-related protein containing RB_A, RB_B, and RB_N domains and a cyclin-like superfamily domain. The product possesses DNA-binding transcription activator activity specific to RNA polymerase II, transcription corepressor binding, and protein serine/threonine kinase activity. RB is associated with negative regulation of the G1/S transition of the mitotic cell cycle, regulation of cytokinesis, stem cell population maintenance, palisade mesophyll development, stomatal complex formation, and heterochromatin organization. It localizes to the microsporocyte nucleus, generative cell nucleus, chromatin silencing complex, and spindle. The gene has been connected to late blight resistance, leaf morphology, flowering time, photosynthetic rate, seed dormancy, root thickness, and salt tolerance. Studies of related genes in other species link the family to cell cycle control, stem cell maintenance, stomatal index, organ size, and drought stress response.