Intracellular localization of the tumor suppressor HtrA1/Prss11 and its association with HPV16 E6 and E7 proteins

J Cell Biochem. 2008 Sep 1;105(1):81-8. doi: 10.1002/jcb.21804.


We have a long-standing interest in a nuclear protease which appears to be involved in carcinogenesis. We recently identified the protease as high temperature requirement factor A 1 (HtrA1), also known as Prss11, which is member of an oxidative stress-response family of proteases. HtrA1 has been classified as a secreted protease involved in TGFbeta signaling, but recent work has shown HtrA1 to be a tumor suppressor. Here we show that processed forms of HtrA1 are found intracellularly and intranuclearly, and the active intranuclear form of HtrA1 shows an approximately Mr 29,000. Further, expression of HPV E6/E7 proteins is associated with a post-transcriptional up-regulation of HtrA1 (most notably the nuclear form), and HtrA1 is found associated with both HPV E6 and E7 proteins.

MeSH terms

  • Cell Line
  • Gene Expression Regulation
  • High-Temperature Requirement A Serine Peptidase 1
  • Humans
  • Intracellular Space / metabolism*
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / metabolism*
  • Papillomavirus E7 Proteins / genetics
  • Papillomavirus E7 Proteins / metabolism*
  • Protein Binding
  • RNA, Messenger / genetics
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Serine Endopeptidases / genetics
  • Serine Endopeptidases / metabolism*


  • E6 protein, Human papillomavirus type 16
  • Oncogene Proteins, Viral
  • Papillomavirus E7 Proteins
  • RNA, Messenger
  • Repressor Proteins
  • High-Temperature Requirement A Serine Peptidase 1
  • HtrA1 protein, human
  • Serine Endopeptidases