He was lost in the cytosol station
He was lost and didn't know where to go
He was lost after exhaustive translation
In a new world that he just didn't know
A protein that was exposed to tRNA in surplus
Was now left to find a way of its own
He felt that in his life there must be a larger purpose
Than stay around the ribosome of where he’d grown

Chorus:
Give me an S-I-G-N-A-L peptide
And I will tell you the pathway forward
If you find a translocon, step right
Into it if you are not a coward
Don’t make the classical mistakes
And let go of all your brakes
The classical pathway it is
If you like to be secreted
And like to experience all secrets,
That if you stay inside the cell you’ll miss
With an S-I-G-N-A-L peptide
You do the classical pathway onward

Through the translocator and into the ER
For this experience he was amused
He showed he didn't have the fear
Of being folded and tightly produced
And then he went for a date but brought a chaperone with him
To show he was sincere of his intention
He was dressed up in the glycan they just had given him
With three glucose as an extension

Chorus

When he removed the final glucose
And dressed with just a COP on his head
He couldn't leave to plasma membrane because
He has to fly into the Golgi instead
He left endoplasmic reticulum in the strangest vehicle
Just surrounded by a lipid bilayer
Of COPII vesicle
He was about to say his final prayer

Chorus

On Golgi airport he finally landed
With all the proteins there was a queue
To Golgi immigration the passport he handed
But the passport was overdue
So he was sent back into ER with a KDEL guard
Where ER embassy has to give a replacement
But in order to be given a temporary entrance card
That he was folded right he has to give a statement

Chorus

Then finally to Golgi his vesicle was fusing
Glycosyltransferases greeted with cheers
All nucleotide sugars the transferases were using
Were offering him their sugar beers
Now both with N-linked and O-linked sugar was equipped
And a Trans-Golgi Network full of friends
Finally to the plasma membrane he was shipped
And this is how this pathway song will end

Chorus

Outro / Call and Response:
Give me an S! – SERINE!
Give me an I! – ISOLEUCINE!
Give me a G! – GLYCINE!
Give me an N! – ASPARAGINE!
Give me an A! – ALANINE!
Give me an L! – LEUCINE!
What is that?
– SIGNAL PEPTIDE!
Can’t hear you!
– SIGNAL PEPTIDE!
One more time!
– SIGNAL PEPTIDE!
Where does it go?
– THROUGH THE SECRETORY PATHWAY!
Where does it end?
– AT THE PLASMA MEMBRANE!