--- a/README.markdown Sat Sep 23 21:42:21 2023 -0400
+++ b/README.markdown Mon Sep 25 11:53:56 2023 -0400
@@ -1011,4 +1011,33 @@
Came up with some absolutely cursed code to made shaded normal graphs.
Surprised that's not already a thing.
+## 2023-09-25
+HG545. Need to retype all my notes for this module here when I get some time so
+I don't lose them.
+
+Today started with a description of RNAseq. Something vaguely familiar was
+a nice change for this class. Then reviewed STARR-seq which I think I mostly
+understand now.
+
+Talked about the similarity between enhancers and promoters. Polymerase can
+sometimes actually sit down at enhancers and produce small RNAs, but
+transcription doesn't ever elongate. But this might be an example of how genes
+could evolve.
+
+Then talked about heat shock proteins and heat shock factor as an example of how
+rapid transcription can happen.
+
+* HSE: "Heat Shock Element", an enhancer sequence located upstream of a gene,
+ e.g. hsp90.
+* hsp90: "Heat Shock Protein 90", a protein that's used in cells to help other
+ proteins fold in the presence of heat that might otherwise prevent it. The 90
+ is from its weight in kilodaltons (lol).
+* HSF1: "Heat Shock Factor 1", a transcription factor that trimerizes, binds to
+ HSE, and recruits another thing to activate the transcription of hsp90.
+
+There's a self-regulation loop here where, when things are cold, hsp90 binds to
+HSF1 outside the nucleus and prevents it from enhancing transcription of hsp90
+(i.e. of itself). But when heat is applied, other proteins unfold and hsp90
+starts chaperoning them more, which leaves HSF1 free to enter the nucleus and
+enhance transcription of hsp90.