Troponin T is the tropomyosin-binding subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity. Binds with troponins I and C to make the thin-filament regulatory complex, troponin. The major isoform in adult heart is CTNT4. Phosphorylation at Thr-216 by PRKCA induces significant reduction in myofilament calcium sensitivity and actomyosin ATPase activity. Belongs to the troponin T family.