MICROCEPHALY in NEURODEVELOPMENTAL DISORDERS: CENTROSOME ALTERATIONS associated with CELL CYCLE REGULATION

• Grant number: 24/20846-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2026
• End date: February 29, 2028
• Field of knowledge: Biological Sciences - Genetics - Human and Medical Genetics
• Principal Investigator: Ana Cristina Victorino Krepischi
• Grantee: Giovanna Cantini Tolezano
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Microcephaly, a major cause of cognitive delay, is primarily characterized as a defect in cell proliferation, abundance, and function. The centrosome is a crucial organelle for the formation and orientation of the mitotic spindle, cell cycle regulation, and ciliogenesis. Several proteins are recruited by the centrosome, notably those with the coiled-coil motif. These proteins, such as those from the CCDC gene family, are involved in organizational and regulatory activities common to centrosome activity and are implicated in various pathologies, such as neurodevelopmental disorders (NDD). Considering that several centrosomal proteins have not yet been identified, we hypothesize that poorly characterized CCDC genes could act at the centrosome and be implicated as a cause of idiopathic cases of microcephaly due to cell cycle disturbances. From this perspective, the central objective of this project is to investigate the relevance of centrosome proteins as a cause of microcephaly and NDD. As guiding axes, we propose: (a) proteomics of human neural stem cell centrosomes; (b) characterization and functional evaluation of CCDC17 and CCDC82 in human cell line - (b1) subcellular localization by indirect immunofluorescence; (b2) knockout via CRISPR-Cas9; (b3) investigation of the effect of knockout on proliferation, cell cycle, apoptosis, and ciliogenesis; (b4) evaluation of cellular phenotype rescue by overexpression of target genes; and (c) exome/genome analysis of idiopathic microcephaly cases, searching for deleterious variants in known centrosome genes, with an emphasis on CCDCs and those resulting from the proteome study of neural cell centrosomes. We aim to contribute with data on the composition of neural cell centrosomes, characterization of two CCDC genes, and their potential impact on molecular mechanisms of microcephaly and neurodevelopmental disorders. (AU)