Retinoic Acid Retinoic Acid Signaling PathwaySignaling Pathway

By: Taylor JohnsonBy: Taylor Johnson

Developmental BiologyDevelopmental Biology

Fact

Retinol is derived from Vitamin A, Retinol is derived from Vitamin A, which can be found in foods such as which can be found in foods such as Squash, Pumpkins, and carrots.Squash, Pumpkins, and carrots.

FactFact

Retinoic Acid is essential in Retinoic Acid is essential in development of the heart, lungs and development of the heart, lungs and kidneys (Duester).kidneys (Duester).

It also functions in the development of It also functions in the development of the embryonic brain and the spinal the embryonic brain and the spinal cord (Duester).cord (Duester).

FactFact

Retinoic Acid plays an essential role in Retinoic Acid plays an essential role in the development of the limbs and the development of the limbs and retina.retina.

So it’s true what they say about eating So it’s true what they say about eating carrots for good eyesight……carrots for good eyesight……

FactsFacts

Too little Retinoic Acid can result in Too little Retinoic Acid can result in craniofacial deformities such as cleft craniofacial deformities such as cleft palate.palate.

Cleft Palate occurs between the fourth Cleft Palate occurs between the fourth and eighth week of pregnancy (Seattle).and eighth week of pregnancy (Seattle).

About 1 in 1000 babies are born with About 1 in 1000 babies are born with cleft palate (Seattle).cleft palate (Seattle).

Pathway Pathway IllustrationIllustration

Embryonic Cell

Nucleus

Alcohol Dehydrogenase

Retinaldehyde Dehydrogenase 2

Retinol enters the cell.

ADH converts the Retinol into Retinaldehyde.

Retinol

Retinaldehyde

RALDH2 converts RALD to Retinoic Acid.

Retinoic Acid

RALD

Retinoic Acid is membrane permeable

Cell Membrane

CRABP

CRABP “grabs” RA as it enters the cell.

Embryonic Target Cell

CRABP takes RA into the nucleus.

RARE DNA binding site

Target Cell

R

X

R

R

A

R

RARE DNA binding site

RA binds to the receptors in the nucleus.

Target Cell

Non Responding Cell

CYP26

In non-responding cells, CYP26 degrades RA.

Degraded RA

ReferencesReferences "Cleft Lip and Cleft Palate | Seattle Children's Hospital." "Cleft Lip and Cleft Palate | Seattle Children's Hospital." Seattle Children's Hospital - World Class Child Health Seattle Children's Hospital - World Class Child Health

Care | Seattle Children's HospitalCare | Seattle Children's Hospital. Seattle Children's Hospital. Web. 13 Oct. 2011. . Seattle Children's Hospital. Web. 13 Oct. 2011. <http://www.seattlechildrens.org/medical-conditions/chromosomal-genetic-conditions/cleft-lip-palate/>.<http://www.seattlechildrens.org/medical-conditions/chromosomal-genetic-conditions/cleft-lip-palate/>.

Maden, Malcom. "Access : Retinoid Signalling in the Development of the Central Nervous System : Nature Maden, Malcom. "Access : Retinoid Signalling in the Development of the Central Nervous System : Nature Reviews Neuroscience." Reviews Neuroscience." Nature Publishing Group : Science Journals, Jobs, and InformationNature Publishing Group : Science Journals, Jobs, and Information. Nature, Nov. 2002. . Nature, Nov. 2002. Web. 13 Oct. 2011. <http://www.nature.com/nrn/journal/v3/n11/full/nrn963.html>.Web. 13 Oct. 2011. <http://www.nature.com/nrn/journal/v3/n11/full/nrn963.html>.

Duester, Gregg. "Cell : Retinoic Acid Synthesis and Signaling during Early Organogenesis." Duester, Gregg. "Cell : Retinoic Acid Synthesis and Signaling during Early Organogenesis." ScienceDirect - ScienceDirect - HomeHome. Science Direct, 19 Sept. 2008. Web. 13 Oct. 2011. . Science Direct, 19 Sept. 2008. Web. 13 Oct. 2011. <http://www.sciencedirect.com/science/article/pii/S0092867408011215><http://www.sciencedirect.com/science/article/pii/S0092867408011215>

Key

Cell Membrane

Retinoic Acid

Retinol

Degraded Retinoic Acid

Cytochrome P450

Alcohol Dehydrogenase

Retinaldehyde Dehydrogenase 2

Retinoid X Receptor

Retinoic Acid Receptor

Retinaldehyde

Cellular Retinoic Acid Binding Protein

Retinoic Acid Receptor Enzyme