Nav: Home

Protein scissors for cellular transport

June 26, 2019

In many ways, a cell is like a city. Proteins or people do daily work to keep the economy going, and items are imported and exported for trade. Imports are shipped into cells by way of endocytosis. Before reaching their final destination, they are kept at the early endosome, a structure that determines whether the material will be disposed, recycled or delivered to a specific region in the cell. A new study in iScience by researchers at the Nara Institute of Science and Technology (NAIST), Japan, demonstrates how ankyrin repeat and KH domain-containing protein 1 (ANKHD1) are instrumental in forming the early endosome.

Endocytosis describes the formation of vesicles at the membrane and then transports inside the cell.

"The cell moves material through vesicles that are cut from the membrane. Only a small number of proteins are known to execute membrane scission, and these proteins include BAR domain proteins," notes NAIST Professor Shiro Suetsugu, who managed the study.

"ANKHD1 contains an ankyrin repeat domain [ARD], which we previously found to have lipid-binding ability," he continues. Ankyrins are proteins that bind to proteins, but their membrane binding capacity is relatively unexplored.

To investigate more about ARD, the study began with 600 candidates, but settled with ANKHD1 when liposome sedimentation assays indicated its ARD had strong vesiculation activity.

The ARD of ANKHD1 contains 25 ankyrin repeats that the scientists divided into one group of 15 and another group of 10. To test the function of these two groups, they established a series of ANKHD1 constructs: one ARD with all 25 ankyrin repeats, one with only the group of 15 and one with only the group of 10, with the first two including the N-terminal, and tested how these constructs reacted with liposomes.

"We found that the two groups had different roles, vesiculation and dimerization," says Suetsugu.

The vesiculation ability of the group of 10 broke liposomes down into small vesicles and was attributed to an amphipathic helix and electrostatic interactions with the liposome, but this ability was enhanced by the dimerization of the group of 15. This process resembled how BAR proteins interact with membranes.

Moreover, reducing the ANKHD1 expression in mammalian cells increased the size of the early endosome, indicating a membrane-deformation function that could impact intracellular trafficking.

"The vesiculation of early endosomes is a crucial and early step in intracellular trafficking, but very little is known about the proteins that regulate this system. Abnormalities at this stage can have a tremendous impact on many cellular functions," says Suetsugu.
-end-
Resource

Title: Membrane-deformation ability of ANKHD1 is involved in the early endosome enlargement

Authors: Manabu Kitamata, Kyoko Hanawa-Suetsugu, Kohei Maruyama & Shiro Suetsugu

Journal: iScience

DOI: 10.1016/j.isci.2019.06.020

Information about Prof. Suetsugu lab can be found at the following website: https://bsw3.naist.jp/suetsugu/?cate=278

Nara Institute of Science and Technology

Related Proteins Articles:

Designing vaccines from artificial proteins
EPFL scientists have developed a new computational approach to create artificial proteins, which showed promising results in vivo as functional vaccines.
New method to monitor Alzheimer's proteins
IBS-CINAP research team has reported a new method to identify the aggregation state of amyloid beta (Aβ) proteins in solution.
Composing new proteins with artificial intelligence
Scientists have long studied how to improve proteins or design new ones.
Hero proteins are here to save other proteins
Researchers at the University of Tokyo have discovered a new group of proteins, remarkable for their unusual shape and abilities to protect against protein clumps associated with neurodegenerative diseases in lab experiments.
Designer proteins
David Baker, Professor of Biochemistry at the University of Washington to speak at the AAAS 2020 session, 'Synthetic Biology: Digital Design of Living Systems.' Prof.
Gone fishin' -- for proteins
Casting lines into human cells to snag proteins, a team of Montreal researchers has solved a 20-year-old mystery of cell biology.
Coupled proteins
Researchers from Heidelberg University and Sendai University in Japan used new biotechnological methods to study how human cells react to and further process external signals.
Understanding the power of honey through its proteins
Honey is a culinary staple that can be found in kitchens around the world.
How proteins become embedded in a cell membrane
Many proteins with important biological functions are embedded in a biomembrane in the cells of humans and other living organisms.
Finding the proteins that unpack DNA
A new method allows researchers to systematically identify specialized proteins called 'nuclesome displacing factors' that unpack DNA inside the nucleus of a cell, making the usually dense DNA more accessible for gene expression and other functions.
More Proteins News and Proteins Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.