<i>Chlamydomonas</i> LZTFL1 mediates phototaxis via controlling BBSome recruitment to the basal body and its reassembly at the ciliary tip
Wei-Yue Sun, Bin Xue, Yan‐Xia Liu, Rui‐Kai Zhang, Rong-Chao Li, Xin Wen, Mingfu Wu, Zhen‐Chuan Fan
Abstract
Significance Bardet–Biedl syndrome (BBS) characteristic of blindness, obesity, and kidney anomalies is a rare human ciliopathy. BBS could result from disrupted ciliary dynamics of the BBSome, a conserved octamer of BBS proteins, which facilitates intraflagellar transport with the ciliary entry and/or removal of signaling proteins. Here, we show that LZTFL1 mediates phototaxis through balancing BBSomes available for transporting into and out of cilia. LZTFL1 controls the BBSome basal body amount available for entering cilia by promoting BBS3 targeting to the basal bodies. LZTFL1 simultaneously promotes BBSome removal out of cilia by stabilizing IFT25/27, a regulator essential for BBSome reassembly at the ciliary tip. LZTFL1 applies this dual-mode system to maintain BBSome ciliary dynamics, providing a mechanistic mechanism for BBS disorder.