Fig. 4: Interplay between OST-A and MPT during multipass protein synthesis.

a, An enrichment scatter plot for multipass-encoding transcripts detected in both OST-A and MPT samples, colored according to the length of the longest translocated segment. b, OST-A and MPT peak maps for the indicated multipass protein types, sorted by the first MPT peak (length >1% of coding sequence). Each row represents a single transcript normalized by coding region length and colored to indicate positions where either OST-A, MPT or both are enriched. The number (N) of each type is indicated. Type II multipass proteins were further classified by the length of the first translocated segment. c, Metagene plots of OST-A (blue) and MPT (magenta) recruitment to type I and type II multipass proteins whose first translocated segment is long, aligned on the end of the indicated feature. The median, interquartile range and number of sequences (N) are indicated. Only transcripts enriched for OST-A and MPT are included. d, Metagene plots of OST-A and MPT dynamics across long (≥100 residue) downstream lumenal segments, aligned to the start of the indicated segment. Only transcripts showing MPT recruitment at the start of the segment were included, and the first translocated segments were excluded from the analysis. The median, interquartile range and number of sequences (N) are indicated. e, OST-A and MPT interaction profiles for NPC1. The mean enrichment (line) and range (shaded) are shown. f, As in d but for long downstream cytosolic segments. Only transcripts showing MPT recruitment at the start of the segment were included, and cytosolic N-tails were excluded from the analysis. g, OST-A and MPT interaction profiles for HMGCR. The mean enrichment (line) and range (shaded) are shown. h, A cartoon illustrating translocon remodeling during synthesis of a hypothetical type 1 multipass protein containing long lumenal and cytosolic segments. i, OST-A and MPT interaction profiles for Piezo1. The mean enrichment (line) and range (shaded) are shown.