Vitamin C may exert variable effects on viability and proliferation of HeLa cells exhibiting high and low chromosomal instability.

Background: Chromosomal instability (CIN), defined as abnormality in chromosome structure or number, is the hallmark of malignancies. The role of vitamin C in cancer treatment is controversial and its effect on CIN is still an open field of research. In this work, we tried to study the effect of high-dose L-ascorbic acid (L-AA) on CIN-induced (CINhi = CIN high) and non-CIN-induced (CINlo = CIN low) cervical cancer cells.

Salmonella exploits the host endolysosomal tethering factor HOPS complex to promote its intravacuolar replication.

Salmonella enterica serovar typhimurium extensively remodels the host late endocytic compartments to establish its vacuolar niche within the host cells conducive for its replication, also known as the Salmonella-containing vacuole (SCV). By maintaining a prolonged interaction with late endosomes and lysosomes of the host cells in the form of interconnected network of tubules (Salmonella-induced filaments or SIFs), Salmonella gains access to both membrane and fluid-phase cargo from these compartments. This is essential for maintaining SCV membrane integrity and for bacterial intravacuolar nutrition.

Arf-like GTPase Arl8: Moving from the periphery to the center of lysosomal biology.

Lysosomes are dynamic organelles that not only mediate degradation of cellular substrates but also play critical roles in processes such as cholesterol homeostasis, plasma membrane repair, antigen presentation, and cell migration. The small GTPase Arl8, a member of Arf-like (Arl) family of proteins, has recently emerged as a crucial regulator of lysosome positioning and membrane trafficking toward lysosomes. Through interaction with its effector SKIP, the human Arl8 paralog (Arl8b) mediates kinesin-1 dependent motility of lysosomes on microtubule tracks toward the cell periphery.

The small GTPase Arl8b regulates assembly of the mammalian HOPS complex on lysosomes.

The homotypic fusion and protein sorting (HOPS) complex is a multi-subunit complex conserved from yeast to mammals that regulates late endosome and lysosome fusion. However, little is known about how the HOPS complex is recruited to lysosomes in mammalian cells. Here, we report that the small GTPase Arl8b, but not Rab7 (also known as RAB7A), is essential for membrane localization of the human (h)Vps41 subunit of the HOPS complex.