L2, the minor capsid protein of papillomavirus

Virology. 2013 Oct;445(1-2):175-86. doi: 10.1016/j.virol.2013.04.017. Epub 2013 May 17.


The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ∼8 kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 is not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2.

Keywords: Daxx; E2; Encapsidation; Furin; HPV; Infection; L1; L2; Minor capsid protein; ND-10; Papillomavirus; SP100.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Biological Transport
  • Capsid Proteins / genetics
  • Capsid Proteins / metabolism*
  • Cell Nucleus / virology
  • DNA, Viral / genetics
  • DNA, Viral / metabolism*
  • Epitopes / metabolism
  • Genome, Viral*
  • Human papillomavirus 16 / genetics
  • Human papillomavirus 16 / metabolism*
  • Human papillomavirus 16 / pathogenicity
  • Human papillomavirus 16 / physiology
  • Humans
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / metabolism*
  • Papillomavirus Infections / pathology
  • Papillomavirus Infections / virology
  • Protein Structure, Tertiary
  • Virus Assembly
  • Virus Internalization


  • Capsid Proteins
  • DNA, Viral
  • Epitopes
  • L2 protein, Human papillomavirus type 16
  • Oncogene Proteins, Viral