The human protein atlas blog

Mad about Mitochondria

Cell Atlas Mitochondria Subcell Atlas

Mikaela Wiking

This week, it is Mitochondrial Disease Awareness Week. Therefore we would like to take the opportunity to talk about the mitochondrial proteome, the work we do within this field, and you will even get to meet one of our researchers, involved in this work.

The mitochondria are distributed throughout the cytoplasm of the cell, each organelle enclosed by a double membrane, the inner one forming the characteristic folds known as cristae. Mitochondria are essential for producing the cell´s need of ATP through cellular respiration, but have also been shown to participate in many other cellular functions, including apoptosis, calcium storage and cellular signaling...Read more

Image of the week - Lysosomes

Image of the week Lysosomes Subcell Atlas

Figure 1. Staining of TMEM192 (green) with DNA (blue) in U-2 OS cells.

Welcome to another HPA image of the week! This week we take a look at another member of the vesicle family, the lysosomes.

In a way, lysosomes can be thought of as the recycling plants of your cells. Lysosomes are small membrane bound vesicular organelles that degrade biomolecules within your cells so that the materials in these molecules can be recycled and used for other cellular processes. Often these biomolecules come from vesicles known as endosomes that bring in materials from outside your cells, however lysosomes are also known to degrade other organelles, and products from within the cell...Read more

Image of the week - Endoplasmic reticulum

Endoplasmic reticulum Image of the week Subcell Atlas

Staining of Calnexin (green) with DNA (blue) in A-431 cells

Welcome back blog fans! After a brief hiatus the image of the week highlights from the HPA are back! This week we are discussing the Endoplasmic reticulum, which is not just difficult to say, but is where many of your proteins are made.

The endoplasmic reticulum (ER) is one of the largest organelles in the cell. It is a delicate membranous network composed of sheets and tubules that spreads throughout the whole cytoplasm and is actually contiguous to the nuclear membrane. Two major forms of the ER can be distinguished: the rough ER and the smooth ER. Both have different functions...Read more

Image of the week - Cytoplasm

Cytoplasm Image of the week Subcell Atlas

Figure 1. Staining of RELA (green) with DAPI (blue) and microtubules (red) in U2 OS cells.

Though frequently overlooked as being a "catch-all" for proteins that don't reside within another organelle, cytoplasmic proteins are anything but.

One important role of proteins in the cytoplasm is the regulation of gene expression. There are two main ways in which gene expression is regulated; when converting the genetic code in your DNA to RNA (transcription), and when converting RNA to proteins (translation). Though transcription (DNA to RNA) occurs in the nucleus, cytoplasmic proteins are often involved in activating transcription factors which then move to the nucleus to perform transcription.

The protein stained in Fig 1...Read more

Image of the week - The tiny but mighty centrosome

Centrosome Image of the week Subcell Atlas

Figure 1. Staining of MKKS (green) with DNA (blue) and microtubules (red) in U-2 OS cells.

Let's have a look at another fascinating compartment of the cell, the centrosome! Located in close proximity to the nucleus, the centrosome is so small that it sometimes suffers from being overlooked. However, despite its humble size it is a very important organelle with great impact on cellular function.

The centrosome was first described in 1888 and has been a very popular organelle to study among biology researchers ever since (Conduit P.T. 2015). The most well characterized function of the centrosome is to serve as the organizing center for the microtubules that build up the internal architecture of the cell, the so-called cytoskeleton...Read more