ARPC2

ARPC2 Full Name

actin related protein 2/3 complex, subunit 2, 34kDa

ARPC2 Introduction

ARPC2 (actin related protein 2/3 complex subunit 2, 34 kDa) is an essential component of the actin-related protein 2/3 (Arp2/3) complex, a conserved seven-subunit protein assembly that controls the formation of branched actin filament networks. As a core structural subunit of the Arp2/3 complex, ARPC2 acts together with ARPC4 to form a clamp-like module that stabilizes the interaction between the complex and pre-existing actin filaments, enabling efficient actin branch formation. Because dynamic actin remodeling is fundamental for cell migration, intracellular trafficking, immune cell activation, and tissue remodeling, abnormal ARPC2 activity may contribute to diseases where cytoskeletal regulation becomes disrupted. Understanding ARPC2 function provides valuable insights for researchers investigating how defects in cellular architecture influence inflammation, fibrosis, cancer progression, and other complex disorders.

Beyond its classical role in actin branching, ARPC2 has emerged as an important regulator of inflammatory responses and fibrotic remodeling. The Arp2/3 complex, including ARPC2, regulates immune cell migration, vascular smooth muscle cell movement, and inflammatory signaling by controlling actin cytoskeleton rearrangement. Recent studies indicate that ARPC2 participates in oxidative stress-induced vascular inflammation through pathways such as p38 MAPK signaling and contributes to abnormal cellular migration during tissue injury repair. In pulmonary fibrosis, ARPC2 has been identified as a potential disease-associated regulator through a noncanonical mechanism independent of the complete Arp2/3 complex. ARPC2 can promote MRTFA (myocardin-related transcription factor A) nuclear translocation and enhance the expression of profibrotic genes, including ACTA2, suggesting that ARPC2 may represent a promising target for understanding and developing new strategies against idiopathic pulmonary fibrosis and other fibrotic diseases.

Structural and mechanistic studies have further highlighted the therapeutic relevance of ARPC2 in actin network regulation. Cryo-electron microscopy analyses have revealed the near-atomic architecture of the Arp2/3 complex at branched actin junctions, demonstrating how the ARPC2–ARPC4 module functions as a molecular clamp to maintain branch stability and coordinate actin filament interactions. More recent research has shown that regulatory proteins such as SPIN90 can activate Arp2/3-mediated bidirectional actin assembly by inducing specific conformational changes involving ARPC2, including alterations in the clamp–twist angle. These findings position ARPC2 as more than a passive structural component; instead, it is a critical molecular regulator connecting actin dynamics with cellular signaling pathways. Targeting ARPC2-related mechanisms may offer new opportunities for investigating fibrosis, immune-related disorders, cancer cell invasion, and other diseases driven by abnormal cytoskeletal remodeling.

Alternate Names for ARPC2

ARPC2; actin related protein 2/3 complex, subunit 2, 34kDa; actin related protein 2/3 complex, subunit 2 (34 kD); actin-related protein 2/3 complex subunit 2; ARC34; p34 Arc; arp2/3 complex 34 kDa subunit; ARP2/3 protein complex subunit 34; PRO2446; p34-Arc; PNAS-139;

• 1.Xing J, et al.; The role of actin cytoskeleton component Arp2/3 in inflammatory response. Front Cell Dev Biol. 2025, 13:1631187.
  2.Du EJ, et al.; ARPC2 Promotes Pulmonary Fibrosis by Regulating MRTFA Activity Independent of the Canonical ARP2/3 Complex. Int J Mol Sci. 2026, 27(6):2729.