Related Experiment Video

Updated: Jun 20, 2026

RNA Interference-based Investigation of the Function of Heat Shock Protein 27 during Corneal Epithelial Wound Healing
08:34

RNA Interference-based Investigation of the Function of Heat Shock Protein 27 during Corneal Epithelial Wound Healing

Published on: September 27, 2016

Heat shock protein 27 mediates repression of androgen receptor function by protein kinase D1 in prostate cancer cells

S Hassan1, M H U Biswas, C Zhang

  • 1Division of Urology, Department of Surgery, University of Massachusetts Medical School, Worcester, MA, USA.

Oncogene
|September 22, 2009
PubMed

Insights

Protein kinase D1 (PKD1) represses androgen receptor (AR) activity in prostate cancer (PC) by phosphorylating heat shock protein 27 (Hsp27). This interaction, mediated by the p38 pathway, inhibits PC cell proliferation.

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cell Signaling

Background:

  • Protein kinase D1 (PKD1) is downregulated in advanced prostate cancer (PC) and affects androgen receptor (AR) function.
  • PKD1 phosphorylates heat shock protein 27 (Hsp27) at serine 82, influencing AR nuclear transport and transcriptional activity.

Purpose of the Study:

  • To investigate the role of Hsp27 as a mediator in PKD1's repression of AR transcriptional activity and prostate cancer cell proliferation.
  • To elucidate the signaling pathway involved in PKD1-mediated Hsp27 phosphorylation.

Main Methods:

  • Co-immunoprecipitation assays to demonstrate interaction between PKD1 and Hsp27.
  • Western blotting to detect Hsp27 phosphorylation at Ser82.
  • Analysis of AR transcriptional activity and prostate cancer cell proliferation under various conditions.

Main Results:

  • PKD1 directly interacts with and phosphorylates Hsp27 at Ser82 in prostate cancer cells.
  • This phosphorylation is dependent on the p38-mitogen-activated protein kinase pathway.
  • PKD1-mediated Hsp27 phosphorylation is essential for the repression of AR transcriptional activity and androgen-dependent prostate cancer cell proliferation.

Conclusions:

  • Heat shock protein 27 (Hsp27) acts as a key mediator in the repression of androgen receptor (AR) function by protein kinase D1 (PKD1) in prostate cancer cells.
  • The p38-dependent phosphorylation of Hsp27 by PKD1 is a critical mechanism controlling AR activity and prostate cancer cell growth.
  • This study provides in vivo evidence linking PKD1, Hsp27, and AR signaling in prostate cancer progression.

More Related Videos

Measuring Endoplasmic Reticulum Stress and Unfolded Protein Response in HIV-1 Infected T-Cells and Analyzing its Role in HIV-1 Replication10:12

Measuring Endoplasmic Reticulum Stress and Unfolded Protein Response in HIV-1 Infected T-Cells and Analyzing its Role in HIV-1 Replication

Published on: June 14, 2024

Related Concept Videos

The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Other Stress Responses in Bacteria01:30

Other Stress Responses in Bacteria

Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...