InterPro domain: IPR028265

This entry includes animal M-phase-specific PLK1-interacting protein (also known as TTDN1) and plant protein SICKLE.

M-phase-specific PLK1-interacting protein (also known as TTD non-photosensitive 1 protein, TTDN1) co-localises with Plk1 at the centrosome in mitosis and the midbody during cytokinesis [ 1 ]. TTDN1 is phosphorylated by cyclin-dependent kinase 1 during mitosis and subsequently interacts with polo-like kinase 1 (PLK1) [ 2 , 2 ]. It may play a role in maintenance of cell cycle integrity by regulating mitosis or cytokinesis [ 3 ]. Mutations in the C7orf11 (TTDN1) gene has been linked to Trichothiodystrophy (TTD), a rare autosomal recessive disorder whose defining feature is brittle hair [ 3 ].

Protein SICKLE is required for development and abiotic stress tolerance, and is involved in microRNA biogenesis [ 4 ] and mRNA splicing [ 5 ]. SICKLE, also known as ROTUNDA 3, may contribute to plant development by phosphatase 2A-mediated regulation of auxin transporter recycling [ 6 ].

1. TTDN1 is a Plk1-interacting protein involved in maintenance of cell cycle integrity. Cell. Mol. Life Sci. 64, 632-40
2. Identification of C7orf11 (TTDN1) gene mutations and genetic heterogeneity in nonphotosensitive trichothiodystrophy. Am. J. Hum. Genet. 76, 510-6
3. Mutations in the C7orf11 (TTDN1) gene in six nonphotosensitive trichothiodystrophy patients: no obvious genotype-phenotype relationships. Hum. Mutat. 28, 92-6
4. Arabidopsis proline-rich protein important for development and abiotic stress tolerance is involved in microRNA biogenesis. Proc. Natl. Acad. Sci. U.S.A. 109, 18198-203
5. The Arabidopsis sickle Mutant Exhibits Altered Circadian Clock Responses to Cool Temperatures and Temperature-Dependent Alternative Splicing. Plant Cell 28, 2560-2575
6. ROTUNDA3 function in plant development by phosphatase 2A-mediated regulation of auxin transporter recycling. Proc. Natl. Acad. Sci. U.S.A. 113, 2768-73