BMP Signaling, Its Inhibitors, and Key Developmental Pathways

Vocabulary flashcards covering BMP signaling, its inhibitors (Chordin, Noggin, Gremlin), and the Wnt, Hippo, and Vitamin A pathways essential for human embryonic development.

Bone Morphogenetic Proteins (BMPs)

A family of growth factors that regulate cell fate, tissue formation, and embryonic patterning; essential for mesoderm formation, cardiac development, and neural tube development.

Mesoderm Formation

Early embryonic process promoted by BMP signaling that gives rise to muscles, bones, blood, and other internal tissues.

Cardiac Development (BMP-dependent)

Formation and patterning of the heart driven in part by BMP activity during embryogenesis.

Neural Tube Development

BMP-regulated process that produces the brain and spinal cord; requires precise BMP levels for proper closure and patterning.

BMP Inhibitors

Proteins such as Chordin, Noggin, and Gremlin that bind BMPs to block receptor interaction and modulate embryonic patterning.

Chordin

Organizer-region protein that binds BMP-2/4/7, dorsalizes the embryo, promotes neural tissue, and helps establish the forebrain and embryonic axis.

Noggin

BMP antagonist with overlapping function to Chordin; supports neural differentiation and head structure formation while maintaining stem-cell pluripotency.

Gremlin

BMP antagonist critical for limb-bud development; regulates BMP activity to ensure proper tissue patterning in limbs and other organs.

Canonical Wnt Pathway

Wnt/β-catenin signaling cascade that controls cell proliferation, differentiation, axis formation, and organogenesis; activated when Wnt ligands bind Frizzled/LRP5/6.

β-Catenin

Key effector of canonical Wnt signaling that, upon stabilization, enters the nucleus to partner with TCF/LEF transcription factors and regulate gene expression.

Frizzled Receptor

Seven-pass transmembrane protein that binds Wnt ligands to initiate canonical and non-canonical Wnt signaling.

LRP5/6 Co-Receptor

Single-pass transmembrane protein that partners with Frizzled to propagate canonical Wnt signaling and stabilize β-catenin.

Hippo Pathway

Mechanosensitive signaling network that controls cell proliferation, apoptosis, and organ size by inhibiting YAP/TAZ through MST1/2 and LATS1/2 kinases.

MST1/2 Kinases

Core Hippo pathway serine/threonine kinases that activate LATS1/2, leading to YAP/TAZ phosphorylation and inactivation.

LATS1/2 Kinases

Downstream Hippo kinases that directly phosphorylate YAP/TAZ to prevent their nuclear translocation.

YAP/TAZ

Transcriptional co-activators inhibited by Hippo signaling; when active, they drive genes promoting cell growth, migration, and stemness.

Vitamin A (Retinol) Pathway

Metabolic conversion of retinol to retinoic acid, a morphogen vital for cell fate specification, patterning, and differentiation in heart, nervous system, and limb development.

RDH10

Retinol dehydrogenase that oxidizes retinol to retinal, the first step in retinoic acid biosynthesis during embryogenesis.

ALDH1A2

Retinaldehyde dehydrogenase that converts retinal to retinoic acid, the active signaling molecule of vitamin A metabolism.

Retinoic Acid

Active metabolite of vitamin A that binds nuclear receptors (RAR/RXR) to regulate gene expression controlling embryonic patterning and organogenesis.