Experimental and Natural Induction of de novo Centriole Formation

Abstract

In cycling cells, new centrioles are assembled in the vicinity of pre-existing centrioles. Although this canonical centriole duplication is a tightly regulated process in animal cells, centrioles can also form in the absence of pre-existing centrioles; this process is termed de novo centriole formation. De novo centriole formation is triggered by the removal of all pre-existing centrioles in the cell in various manners. Moreover, overexpression of polo-like kinase 4 (Plk4), a master regulatory kinase for centriole biogenesis, can induce de novo centriole formation in some cell types. Under these conditions, structurally and functionally normal centrioles can be formed de novo. While de novo centriole formation is normally suppressed in cells with intact centrioles, depletion of certain suppressor proteins leads to the ectopic formation of centriole-related protein aggregates in the cytoplasm. It has been shown that de novo centriole formation also occurs naturally in some species. For instance, during the multiciliogenesis of vertebrate epithelial cells, massive de novo centriole amplification occurs to form numerous motile cilia. In this review, we summarize the previous findings on de novo centriole formation, particularly under experimental conditions, and discuss its regulatory mechanisms.

Duplication and Segregation of Centrosomes during Cell Division

“…The presence of the centrosome might be necessary to limit duplication: each centriole giving birth to only one centriole. Indeed, de novo centriole amplification can be obtained by overexpressing PLK4 only after having removed the existing centrosome implying that its presence is limiting duplication [ 91 ].…”

GPER1 links estrogens to centrosome amplification and chromosomal instability in human colon cells

“…Whether and how (xeno)estrogen-activated GPER1 might be involved in this pathway and whether other important regulatory proteins of centriole biogenesis such as STIL or the Plk4-recruiting factors Cep192 and Cep152 are also involved ( 75 , 76 ) remains an interesting question for future studies. Of note, centriole overduplication can also arise from de novo centriole assembly, which is normally driven in the absence of pre-existing centrioles ( 77 ). Importantly, sufficiently high levels of cytoplasmic Plk4 can trigger the de novo pathway in human cultured cells, regardless of the presence or absence of pre-existing centrioles ( 78 ).…”

Towards understanding centriole elimination

“…Whereas centriole number increases from 2 to 4 in cycling cells (figure 2a), centriole number control differs in other settings. For instance, some cells are devoid of centrioles to start with and then form them de novo (reviewed in [61]). This is the case for example in early rodent embryos or in some plant groups, including bryophytes, pteridophytes and gymnosperms, as well as in the excavate Naegleria gruberi upon amoeboid to flagellate transformation [62][63][64][65][66].…”