Novel insight into Y-box binding protein 1 in the regulation of vascular smooth muscle cell proliferation through targeting GC box-dependent genes

• Y-box binding protein 1 (YB1) binds directly to GC boxes in target gene promoters.
• All-trans-retinoic acid (ATRA) influences YB1 recruitment to GC boxes in VSMCs. YB1 binds to GC boxes via amino acids 125–220.
• YB1 functions as a transcription activator or suppressor depending on gene context.
• The YB1 C-terminal tail domain suppresses VSMC proliferation.

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is a key event in atherosclerosis and restenosis. In this paper, we report that Y-box binding protein 1 (YB1) functions as a phenotypic regulator in VSMC proliferation-differentiation switching through targeting GC box-dependent genes. Oligo pull-down assays demonstrated that YB1 binds directly to GC boxes via amino acids 125–220. YB1 C-terminal tail domain (CTD, amino acids 125–324) regulates GC box-dependent target gene transcription and suppresses VSMC proliferation. These findings provide a novel insight into the regulation of GC box-related genes by YB1, and provide a new understanding of VSMC proliferation regulation.