Bio H97 Lecture 4: Gene Expression - Cis-Regulation

Ch. 8.3 (291-292) Ch. 13 (480-484)

Cis-Acting Regulatory Sequence

sequences to which proteins bind to regulate transcription of genes located on same chromosome as sequences

Cis-Regulating Element (DNA)

DNA sequences that regulate transcription of genes located on same chromosome; include enhancers, silencer, and core promoter elements

Silencer (DNA)

eukaryotic cis-acting DNA regulatory sequence to which transacting factors bind to repress transcription

Repressor (Protein)

transcription factor that binds to regulatory sequences associated with gene and represses that gene's expression

Enhancer (DNA)

eukaryotic cis-acting DNA regulatory sequences to which transacting factors bind and stimulate transcription

Activator (Protein)

transcription factor that binds to regulatory sequences associated with gene and upregulates that gene's expression

Non-Template/Coding Strand

nontemplate strand of DNA that has same 5'-to-3' polarity as its transcript and same sequence, except for T in DNA and U in RNA

Transcription Factor

proteins that bind promoters and are functional in transcription

Insulator

Cis-acting sequence that act to prevent cross-talk between regulatory elements of adjacent gene and are located between enhancers and promoters of gene that are to be insulated from effects of enhancer

Sonic Hedgehog Gene (Shh)

crucial gene playing significant role in formation and patterning of various structures (limbs) in vertebrates

Housekeeping Genes

genes that have essential cellular or physiological functions

Gene

physical unit of heredity, composed of DNA sequence that is transcribed and encodes polypeptide or another functional molecule

Lactase Gene (LCT)

responsible for encoding enzyme lactase, an enzyme used to digest lactose, a sugar in mammalian milk; mutations in gene lead to lactose intolerance

Transgene

gene that has been modified in vitro by recombinant DNA technology and introduced into genome via transformation

Consensus Sequence

nucleotide sequence in DNA segment derived by comparing sequences of similar segments from other genes/organisms; most commonly occurring nucleotides at each position comprise the sequence

Template Strand

DNA strand serving as template for synthesis of complementary nucleic acid strand

Cell-Type-Specific Genes

genes expressed only in particular cell types within multicellular organisms; crucial for differentiation and function of cell types