Name: steroid hormones and intracellular receptors
Uploaded: 2026-08-26T08:20:23.185Z
Duration: 1 min 56 s
Channel: JoVE

Internal receptors are soluble proteins found in either the cytoplasm or the nucleus. They bind signaling molecules called ligands inside the cell and trigger cellular responses, such as changes in gene expression.Typically, ligands that bind to internal receptors are hydrophobic, nonpolar molecules that can diffuse through the plasma membrane without needing a membrane receptor. Some signaling molecules can also be synthesized inside the target cell.Once a ligand binds, the receptor changes shape and interacts with other regulatory elements in the cell.For example, the hormone testosterone, or its converted form dihydrotestosterone, also called DHT, binds to androgen receptors located in the cytoplasm.After binding, the receptor-ligand complex changes structure and exposes its DNA-binding region. This change also allows the receptors to form dimers and move into the nucleus.Inside the nucleus, the activated receptor binds to specific DNA sequences called hormone-response elements. In androgen signaling, these sequences are called androgen-response elements.By binding to these DNA sequences, the receptor recruits other cellular machinery that helps regulate gene activity by increas

internal receptors

Internal Receptors

Many cellular signals are hydrophilic and therefore cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross the hydrophobic core of the plasma membrane and bind to internal, or intracellular, receptors that reside within the cell. Many mammalian steroid hormones use this mechanism of cell signaling, as does nitric oxide (NO) gas.

Similar to membrane-bound receptors, binding of a ligand to a receptor located in the cytoplasm or nucleus of a cell causes a conformational change in the receptor. Like transcription factors, the active receptor can bind to receptor-specific DNA binding sites to increase or decrease the transcription of target genes. In the case of an intracellular receptor located in the cytoplasm, the receptor-ligand complex must first cross the nuclear membrane.

Many steroid hormones, including estrogen and testosterone, use intracellular receptors to induce specific effects. As an example, estrogen can diffuse across the membrane; binding of estrogen to its receptor results in dimerization of the receptors and transport of the ligand-receptor complex to the nucleus. Once in the nucleus, the complex can bind to DNA sequences called Estrogen-Response Elements (EREs). Depending on the other transcription factors and co-activators, binding of activated estrogen receptors (ERs) to EREs may cause an increase or decrease in transcription of target genes.

The activation of other intracellular receptors, including some thyroid hormone receptors, requires that ligands cross both the plasma membrane and nuclear membrane, as the corresponding receptors reside in the nucleus. These ligand-receptor complexes then can bind to DNA, similar to the mechanism described above.

Many cellular signals are hydrophilic and therefore cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross ...

https://cloudfront.jove.com/files/ftp_upload/11011/11011_article_thumb_11011.jpg

Education

JoVE Core

Biology

Cellular Processes

Cell Signaling

KEY TERMS AND CONCEPTS

steroid hormones and intracellular receptors

Steroid hormones and other small signaling molecules can pass through the cell membrane and bind to intracellular receptors inside the cell. These receptors are also called internal receptors. Many hydrophilic signals cannot cross the plasma membrane, so this pathway is used by signals that are small or hydrophobic. Nitric oxide, or NO, also uses this type of signaling.

When a ligand, which is a signaling molecule, binds to a receptor in the cytoplasm or nucleus, the receptor changes shape. The active receptor can then act like a transcription factor. It binds to specific DNA sites and can increase or decrease the transcription of target genes. If the receptor is in the cytoplasm, the ligand-receptor complex must first move through the nuclear membrane.

Estrogen and testosterone are examples of steroid hormones that use intracellular receptors to trigger effects. Estrogen can diffuse across the membrane and bind its receptor. This binding causes the receptors to dimerize, which means two receptors join together, and the complex moves to the nucleus. There, it binds to DNA sequences called Estrogen-Response Elements, or EREs.

Once the estrogen receptor is attached to EREs, other transcription factors and co-activators help determine the result. The activated receptor may increase or decrease transcription of target genes. Some thyroid hormone receptors also work inside the nucleus. Their ligands must cross both the plasma membrane and the nuclear membrane before the receptor-ligand complex can bind DNA.

Steroid Hormones and Intracellular Receptors

steroid-hormones-and-intracellular-receptors

what is cell signaling?

How Cells Send and Receive Signals

Cell signaling lets cells send and receive messages from the environment and from other cells. Even with a protective membrane, cells need to detect changes and respond to them. Unicellular and multicellular organisms use signaling to stay coordinated and to react to outside cues. Cells often rely on receptor proteins in the membrane to sense information. Skin cells can respond to touch, and photoreceptors in the retina can detect light. Most cells respond to chemical signals such as hormones,...

Steroid hormones and other small signaling molecules can pass through the cell membrane and bind to intracellular receptors inside the cell. These receptors are also called internal receptors. Many hydrophilic signals cannot cross the plasma membrane, so this pathway is used by signals that are small or hydrophobic. Nitric oxide, or NO, also uses this type of signaling. When a ligand, which is a signaling molecule, binds to a receptor in the cytoplasm or nucleus, the receptor changes shape.

contact-dependent cell communication

Cell-to-Cell Signaling via Channels

Cell-to-cell signaling can happen when neighboring cells are in direct contact. In this kind of communication, cells use receptor-ligand interactions or special cytoplasmic channels to move small molecules between them. In animal cells, these channels are called gap junctions. They form when six proteins called connexins assemble into a cylindrical structure in the plasma membrane called a connexon. When connexons from two adjacent cells line up, a channel opens between the cells. Enzymes help...

autocrine signaling

Self-Signaling Cells in Immunity and Cancer

Autocrine signaling is a cell communication method in which a cell sends a signal to itself. The same cell releases an extracellular signaling molecule and also has receptors that can bind to that molecule. This lets the cell respond to its own message. In the immune system, this process is important for homeostasis, or keeping body conditions stable. A well-studied example is the macrophage, an immune cell that secretes cytokines such as interleukin-1, or IL-1. Macrophages also have membrane...

paracrine signaling

Local Cell Signaling in Blood and Healing

Local cell signaling helps cells communicate with nearby neighbors using released signaling molecules. These molecules act only over a short distance because they break down quickly or are inactivated if they are not taken up. This type of signaling supports processes such as nitric oxide signaling in blood vessels, neuron-to-neuron communication at synapses, blood clotting, tissue repair, and local allergic skin reactions. A clear example is nitric oxide signaling in blood vessels. The...

synaptic signaling

Chemical and Electrical Synapses

Neurons send signals across synapses, which are junctions between cells. These signals can excite or inhibit other neurons or target cells such as muscles. Most synapses are chemical. Some are electrical. Chemical synapses use action potentials, which are electrical impulses, to trigger the release of neurotransmitters. The sending neuron is the presynaptic neuron, and the receiving neuron is the postsynaptic neuron. An action potential travels along the axon and reaches the axon terminal,...

endocrine signaling

Hormones Travel to Distant Target Cells

Endocrine signaling uses hormones to send messages to target cells in other organs. Endocrine cells release these hormones into the circulatory system, which carries the signal through the body. Because the hormone reaches the whole organism, only cells with the right receptors respond. This kind of signaling usually acts slowly, but its effects last longer. Endocrine cells can use cell surface receptors or intracellular receptors, depending on the hormone. Cell surface receptors are...

bacterial signaling

Quorum Sensing in Bacteria

Quorum sensing lets bacteria coordinate behavior by sensing how many cells are nearby. Bacteria can signal inside the cell or between cells. When many bacteria act together, they can behave like a community and change gene expression as a group. This signaling starts with autoinducers, or AIs. Individual bacteria make AIs and release them across the cell membrane into the surrounding space. Some AIs diffuse out passively along a concentration gradient, while others are moved out by active...

yeast signaling

Yeast Cell Communication in Mating

Yeast cell communication helps control mating, colony growth, and other cell responses. Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes with a nucleus. Their signaling works much like cell signaling in other eukaryotic cells. A signal often begins when a ligand, such as a protein or small molecule released from a yeast cell, binds to a receptor on the cell surface. This binding activates second-messenger kinases, which then switch transcription factors on or off.

g protein-coupled receptors

GPCR Signaling Through G Proteins

G-protein coupled receptors, or GPCRs, start cell signaling after a ligand binds to the receptor. The receptor is a single polypeptide that crosses the cell membrane seven times. These membrane loops create an outside pocket that fits a specific ligand, such as a neurotransmitter or hormone. The inside loops connect to a G-protein.

enzyme-linked receptors

Trk Receptors in Cell Signaling

Trk receptors are enzyme-linked receptors that help cells respond to growth factors and some hormones. They belong to the receptor tyrosine kinase, or RTK, family. These receptors can trigger several signals inside a cell after they are activated. Neurotrophin receptors are one RTK group and include TrkA, TrkB, and TrkC, which are tropomyosin-related kinase receptors. TrkA binds nerve growth factor, neurotrophin-6, and neurotrophin-7. TrkB binds brain-derived neurotrophic factor, or BDNF, and...

ion channels

Ion Channels in Cells and Membranes

Ion channels are membrane proteins that help cells move ions across the plasma membrane. Ions such as sodium, potassium, and calcium move into and out of cells to maintain the electrochemical gradient. This gradient supports cell size and volume, nerve signaling, and gas and nutrient exchange. Ion channels are specialized integral membrane proteins that let specific ions pass down their electrochemical gradient. Their main job is to help keep the membrane potential, which is needed for cell...

what are second messengers?

Cell Signals That Use Second Messengers

Cell signals often use second messengers to carry messages inside the cell. Many receptor-binding ligands are hydrophilic, so they do not cross the cell membrane. Instead, the signal is relayed to an internal messenger that can spread the message farther. G-protein coupled receptors can activate the phosphoinositol pathway and the cyclic AMP, or cAMP, pathway. In the phosphoinositol pathway, the receptor activates phospholipase C. This enzyme hydrolyzes phosphatidylinositol biphosphate, or...

intracellular signaling cascades

Cell-Surface Receptor Signal Cascades

Cell-surface receptor signal cascades move information from outside the cell into the cytoplasm. This process is called signal transduction. It happens only with cell-surface receptors, because they cannot interact with most cell parts, such as DNA. Internal receptors are different. They can interact directly with DNA in the nucleus and help start protein synthesis. When a ligand binds to a receptor, the receptor changes shape. That shape change affects the receptor’s intracellular domain or...

key terms and concepts

Explore how steroid hormones, estrogen, testosterone, and nitric oxide cross the membrane and activate intracellular receptors to regulate gene transcription.

Steroid Hormones and Intracellular Receptors | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

Steroid Hormones and Intracellular Receptors

Description

Transcript

Tags