"Free (that is, unbound) steroids enter the cell cytoplasm and interact with their receptor. In this process heat shock protein is dissociated, and the activated receptor-ligand complex is translocated into the nucleus.
After binding to the ligand (steroid hormone), steroid receptors often form dimers. In the nucleus the complex acts as transcription factors, augmenting or suppressing transcription of particular genes by its action on DNA. As a result messenger RNA is produced that exits the nucleus and interacts with ribosomes. There, after translation of the genetic message, specific proteins are produced. These specific proteins perform a biological task.
Type II receptors are located in the nucleus. Thus their ligands pass through the cell wall and cytoplasm and enter the nucleus, where they activated the receptor without release of hsp. The activated receptor interacts with the hormone response element, and the transcription process is initiated as with type I receptors."
And a dimer is (in case you don't know)
"Dimers are most often observed in signaling. They are crucial to understanding chemical reactions in biochemistry as well. In this case, a dimer is a protein complex made up of two subunits that are not necessarily covalently linked. In fact, they may initially be monomeric proteins. These monomers will dimerize, or join together, usually upon the binding of a signal to the receptor of each monomer. These signals can be a growth factor, a phosphate group from Adenosine triphosphate (usually through a kinase protein), or a ligand.
An example of this dimerizing activity involves the RAS-independent receptor tyrosine kinase that activates Phospholipase C-gamma. When a growth factor binds to two monomeric Epithelial Growth Factor (EGF) receptor (or Platelet-Derived Growth Factor (PDGF) receptor), the receptors will dimerize and phosphorylate each other at the SH2 binding domains on the cytoplasmic portion of the receptor. The Phospholipase C-gamma isoform has SH2 domains that bind to the newly phosphorylated SH2 binding domain of the dimerized growth factor receptors. Upon binding, the Phospholipase C-gamma will be activated, and will be close to the membrane phospholipid that it is designed to cleave."
