Biology subjects

Makinen, M.

Publications and source records attributed to Makinen, M..

2 recordsLinked to original sources

bioRxiv2021

Influence of warming temperatures on coregonine embryogenesis within and among species

The greatest known global response of lakes to climate change has been an increase in water temperatures. The responses of many lake fishes to warming water temperatures are projected to be inadequate to counter the speed and magnitude of climate change. We experimentally evaluated the responses of embryos from a group of cold, stenothermic fishes (Salmonidae Coregoninae) to increased incubation temperatures. Study groups included cisco (Coregonus artedi) from lakes Superior and Ontario (USA), and vendace (C. albula) and European whitefish (C. lavaretus) from Lake Southern Konnevesi (Finland). Embryos from artificial crossings were incubated at water temperatures of 2.0, 4.5, 7.0, and 9.0{degrees}C, and their responses were quantified for developmental and morphological traits. Embryo survival, incubation period, and length-at- hatch were inversely related to incubation temperature whereas yolk-sac volume increased with incubation temperature within study groups. However, varying magnitudes of responses among study groups suggested differential levels of developmental plasticity to climate change. Differential levels of parental effects indicate genetic diversity may enable all study groups to adapt to cope with some degree of changing environmental conditions. Our results suggest that the coregonines sampled within and among systems may have a wide range of embryo responses to warming incubation conditions.

ecology↗

bioRxiv2021

SLC4A2 Anion Exchanger Promotes Tumor Cell Malignancy via Enhancing H+ Leak across Golgi Membranes

Proper functioning of each secretory and endocytic compartment relies on its unique pH micro-environment that is known to be dictated by the rates of V-ATPase-mediated H+ pumping and its leakage back to the cytoplasm via an elusive "H+ leak" pathway. Here, we show that this proton leak across Golgi membranes involves AE2a (SLC4A2a)-mediated bicarbonate-chloride exchange, as it is strictly dependent on both bicarbonate import (in exchange of chloride export) and the AE2a expression level in the cells. Imported bicarbonate anions and luminal protons then facilitate a common buffering reaction that yields carbon dioxide and water before their egress back to the cytoplasm via diffusion or water channels. The high surface-volume ratio of flattened Golgi cisternae helps this process, as their shape is optimal for water and gas exchange. Interestingly, this pathway is often upregulated in cancers and established cancer cell lines, and responsible for their markedly elevated Golgi resting pH and attenuated glycosylation potential. Accordingly, AE2 knockdown in SW-48 colorectal cancer cells was able to restore these two phenomena, and at the same time, to reverse cells invasive and anchorage-independent growth phenotype. These findings suggest that a malignant cell can be returned to a benign state by normalizing its Golgi resting pH.

cancer biology↗