Cortical ER protein involved in ER-plasma membrane tethering%3B one of 6 proteins (Ist2p%2C Scs2p%2C Scs22p%2C Tcb1p%2C Tcb2p%2C Tcb3p) that connect ER to the plasma membrane (PM) and regulate PM phosphatidylinositol-4-phosphate (PI4P) levels by controlling access of Sac1p phosphatase to its substrate PI4P in the PM%3B localized to the bud via specific mRNA transport%3B non-tagged protein detected in a phosphorylated state in mitochondria%3B C-termini of Tcb1p%2C Tcb2p and Tcb3p interact