Cdx proteins

Caudal homeobox proteins (Cdx) are a family of proteins that control the spatial development of the caudal (rear) area of the embryo in multicellular animals . They perform this function through their property as transcription factors , i.e. through binding to DNA and controlling its transcription .

Human Cdx Proteins

Three Cdx proteins are known in humans: Cdx-1, Cdx-2 and Cdx-4.

Cdx-1 ( gene name: CDX1 ) is 265 amino acids long and has two isoforms. UniProt P47902
Cdx-2 (gene name: CDX2 ) is 313 amino acids long. UniProt Q99626
Cdx-4 (gene name: CDX4 ) has 284 amino acids. UniProt O14627

Functions

The effect of the Cdx proteins as transcription factors was investigated in mice and affects genes in undifferentiated tissue types. The times of intervention are in the early embryonic stage and - in the case of Cdx-2 - in the adult organism. Several Hox genes have cis elements with binding sites for Cdk proteins that act as repressors there.

The expression of Cdx-1 and -2 increases steadily from the small intestine to the large intestine , which causes the spatial differentiation pattern of the intestinal tissue during embryonic development. The interaction of Cdx-1 and -2 with HoxC8 and HoxA9 defines the development of the neural tube and vertebral bodies . Cdx-4 acts as a repressor of HoxA5 expression and this is crucial for the posterior delimitation of this expression.

In the adult organism only Cdx-2 plays a role; its expression is stimulated by laminin -1 and provides a signal cascade for the differentiation and attachment of intestinal epithelial cells.

literature

J. Langman, Embryology médicale, Édition Masson, 1984, Paris.

Individual evidence

↑ Lohnes D: The Cdx1 homeodomain protein: an integrator of posterior signaling in the mouse . In: Bioessays . 25, No. 10, October 2003, pp. 971-80. doi : 10.1002 / bies.10340 . PMID 14505364 .
↑ Gaunt SJ, Drage D, Trubshaw RC: Increased Cdx protein dose effects upon axial patterning in transgenic lines of mice . In: Development . 135, No. 15, August 2008, pp. 2511-20. doi : 10.1242 / dev.015909 . PMID 18579683 .
↑ John A. Walker-Smith, Simon Murch: Diseases of the small intestine in childhood. 4th ed., Informa, 1999. ISBN 1901865037 . P. 17ff.
↑ van den Akker E, Forlani S, Chawengsaksophak K, et al. : Cdx1 and Cdx2 have overlapping functions in anteroposterior patterning and posterior axis elongation . In: Development . 129, No. 9, May 2002, pp. 2181-93. PMID 11959827 .
↑ Tabariès S, Lapointe J, Besch T, et al. : Cdx protein interaction with Hoxa5 regulatory sequences contributes to Hoxa5 regional expression along the axial skeleton . In: Mol. Cell. Biol . 25, No. 4, February 2005, pp. 1389-401. doi : 10.1128 / MCB.25.4.1389-1401.2005 . PMID 15684390 . PMC 548006 (free full text).
^ Moon RT, Bowerman B, Boutros M, Perrimon N: The promise and perils of Wnt signaling through beta-catenin . In: Science . 296, No. 5573, May 2002, pp. 1644-6. doi : 10.1126 / science.1071549 . PMID 12040179 .

[1] Lohnes D: The Cdx1 homeodomain protein: an integrator of posterior signaling in the mouse . In: Bioessays . 25, No. 10, October 2003, pp. 971-80. doi : 10.1002 / bies.10340 . PMID 14505364 .

[2] Gaunt SJ, Drage D, Trubshaw RC: Increased Cdx protein dose effects upon axial patterning in transgenic lines of mice . In: Development . 135, No. 15, August 2008, pp. 2511-20. doi : 10.1242 / dev.015909 . PMID 18579683 .

[3] John A. Walker-Smith, Simon Murch: Diseases of the small intestine in childhood. 4th ed., Informa, 1999. ISBN 1901865037 . P. 17ff.

[4] van den Akker E, Forlani S, Chawengsaksophak K, et al. : Cdx1 and Cdx2 have overlapping functions in anteroposterior patterning and posterior axis elongation . In: Development . 129, No. 9, May 2002, pp. 2181-93. PMID 11959827 .

[5] Tabariès S, Lapointe J, Besch T, et al. : Cdx protein interaction with Hoxa5 regulatory sequences contributes to Hoxa5 regional expression along the axial skeleton . In: Mol. Cell. Biol . 25, No. 4, February 2005, pp. 1389-401. doi : 10.1128 / MCB.25.4.1389-1401.2005 . PMID 15684390 . PMC 548006 (free full text).

[6] Moon RT, Bowerman B, Boutros M, Perrimon N: The promise and perils of Wnt signaling through beta-catenin . In: Science . 296, No. 5573, May 2002, pp. 1644-6. doi : 10.1126 / science.1071549 . PMID 12040179 .