What is the Origin of PR-A?

PR-A originates from the single human progesterone receptor gene, PGR, located on chromosome 11, but is transcribed from an alternative, downstream promoter site. The two distinct protein isoforms, PR-A and PR-B, are products of differential messenger RNA transcription from the same gene. The discovery of these distinct isoforms in the late 20th century provided a molecular basis for the complex, tissue-specific actions of progesterone.

What is the Mechanism of PR-A?

PR-A exerts its effects by forming heterodimers with PR-B, and this complex then binds to Progesterone Response Elements on the DNA. Because PR-A lacks the potent Activation Function-3 domain present in PR-B, the resulting PR-A/PR-B heterodimer exhibits reduced transcriptional activity compared to a PR-B homodimer. This inhibitory mechanism allows PR-A to modulate the intensity of progesterone signaling, providing a fine-tuned, cell-specific control over gene expression related to reproductive and endocrine tissue development.

PR-A ∞ Area

PR-A

Meaning

PR-A, or Progesterone Receptor-A, is one of the two principal isoforms of the human progesterone receptor protein, a nuclear receptor activated by the steroid hormone progesterone. PR-A is structurally shorter than its counterpart, PR-B, lacking a unique N-terminal activation domain. Functionally, PR-A often acts as a dominant negative regulator, serving to antagonize or dampen the transcriptional effects mediated by the PR-B isoform.

$A fractured, spherical form reveals a luminous orb at its core, supported by intricate branching structures. This symbolizes Hormonal Imbalance affecting Cellular Health during Andropause. The radiant core signifies Endocrine System Homeostasis and Reclaimed Vitality through Personalized Medicine Protocols like Testosterone Replacement Therapy and Advanced Peptide Protocols.$

What Are the Specific Receptor Interactions of Micronized Progesterone in Vascular Cells?

Micronized progesterone interacts with nuclear, membrane, and mitochondrial receptors in vascular cells to regulate gene expression and rapid signaling.

∞ Vascular Permeability
∞ PR-A
∞ Membrane Receptors

HRTioAugust 2, 2025

PR-A

Meaning

Origin

Mechanism

What Are the Specific Receptor Interactions of Micronized Progesterone in Vascular Cells?

Provided by the clinical team
at 4Ever Young Miami Dadeland

-15% ∞ HRTIO15

Your protocol begins with a conversation.

Visit

Schedule Appointment

About

Med & Wellness

4Ever Young Miami Dadeland

Communication

+1 786-529-6686

Email Us

Opening Hours