Lecture 10: Biosynthesis of Steroid Hormones Flashcards
modes of cell-cell communication
-juxtacrine signaling
-endocrine signaling
-paracrine signaling
-synaptic/neuronal signaling
-autocrine signaling
Juxtacrine signaling
-direct physical contact
Endocrine signaling
-travels far through blood to target organ
-low concentration
-high affinity receptors
-minutes to hours
Paracrine signaling
-travels short distance
-affects neighboring cells
-rapid and localized communication
synaptic/neuronal signaling
-neurotransmitter
-short distance
-high local concentration
-dissociate rapidly
-millisecond termination
autocrine signaling
-made and functions in same cell
Steroid hormone structure
-made from cholesterol
-planar, rigid, hydrophobic
-tight binding to receptors
-low concentrations in body
-bound to serum carrier proteins
Steroid hormone action
-diffuse through cell membrane
-bind steroid hormone receptor
-regulate transcription of a specific set of genes
Classes of steroid hormones
-sex and progestational hormones
-adrenocortical hormones
sex and progestational hormones
-progesterone
-17B-estradiol
-testosterone
Adrenocortical hormones
-Cortisol
-Aldosterone
structure of steroid hormones
-share 4 rings of cholesterol
Steroid receptors
-intracellular
-bind steroid hormones
-regulate transcription of specific set of genes
-belong to nuclear family
Steroid receptor structure
-DNA-binding domain
-hormone-binding domain
Hormone Responsive Elements (HRE)
-specific DNA seq
-binds to active, dimerized steroid receptors
-binds DNA-binding domain
-alters rate of transcription