Sanchez-Huertas et al. demonstrate that the +TIP Navigator-1 (NAV1) couples F-actin and microtubules in the growth cone of cortical axons. This property enables NAV1 to promote microtubule persistence in the growth cone periphery and controls growth cone dynamics and steering.
Chen et al. define the role of the N-terminal domain (TD) of clathrin heavy chain in early and late stages of clathrin-mediated endocytosis (CME) and design a membrane-permeant peptide, Wbox2, that acutely and potently inhibits CME.
The tumor suppressor PTEN is essential for epithelial morphogenesis. Qi et al. identify Abi1, a core adaptor protein in the WAVE regulatory complex, as a new PTEN substrate. PTEN dephosphorylates Abi1 and causes Abi1 degradation through calpains and thus down-regulates the WAVE regulatory complex to induce epithelial differentiation and polarization.
A single alternatively spliced exon in the CLTC gene contributes to clathrin coat organization. This event participates in the plasticity from clathrin-coated pits to plaques, structures that are essential for muscle fiber function and maintenance.
The centralspindlin complex, comprising Tumbleweed RhoGAP and kinesin-like Pavarotti proteins, associates with microtubules during cytokinesis. Nakamura et al. show that Pavarotti has centralspindlin complex–independent functions, binds directly to actin, and regulates actin dynamics during cell wound repair and oogenesis.
Damaged mitochondria are selectively eliminated by Parkin/PINK1-mediated autophagy. Yamano et al. show that in addition to binding ATG8 proteins, one of the critical autophagy adaptors, OPTN, possesses an ATG9A binding site that contributes to de novo synthesis of autophagosomal membranes.
Jiang and colleagues investigate how locations of sites of organelle assembly are determined during cell division in the ciliate Tetrahymena thermophila. They find that correct placement of new organelles involves antagonistic influences of a cyclin E and a Hippo/Mst kinase.
Branched actin networks are assembled on microtubules by adenomatous polyposis coli for targeted membrane protrusion
Efimova et al. show that adenomatous polyposis coli (APC) at microtubule tips triggers assembly of a branched actin network when the microtubule hits the plasma membrane in neuronal growth cones. These findings uncover a new mechanism of microtubule-dependent cell navigation.
Dopie et al. apply TSA-MS ratio, an approach that compares the abundance of proteins in nuclear speckles with centromeres to reduce nonspecific background, and show that MFAP1 levels modulate nuclear speckle size and MFAP1 is recruited early to reforming nuclear speckles after mitosis.
Paul et al. use cryo-ET to show that microtubules can contain actin filaments in their lumen. Two types of F-actin structure are distinguished, Class I and Class II, with slightly different helical symmetries and outer microtubule diameters. They call these filaments microtubule lumenal actin (ML-actin).
Chan et al. show that natural killer (NK) cells can be reprogrammed by breast cancer cells to promote metastasis. Reprogramming can be blocked by targeting NK cell inhibitory receptors TIGIT or KLRG1 or inhibiting DNA methyltransferases, which suggests new approaches to prevent or treat metastasis.
Grond et al. show that GRASPs or GORASPs do not have a role in stacking of Golgi cisternae in vivo but instead are required for linking cisternal rims to likely control flux of transport through the Golgi apparatus.