1. Clathrin-coated - go to lysosomes or PM
2. COP1 - go from CGN to ER
3. COP2 - go from ER to CGN

1. cargo proteins bind to sorting signal membrane receptors
2. transmembrane proteins have a cytoplasmic sorting signal that attaches to extracellular cargo or adaptor proteins
3. cytoplasmic adaptor proteins bind sorting signal of TMProtein and coat proteins
4. Coat proteins bind to adaptor proteins or TMP sorting signal to form vesicle

1. Vesicular transport Model - vesicles transport cargo from CGN to cis cisternae to medial to trans cist to TGN
2. Cisternal Maturation Model - Cisternae are made at CGN and change identity through the backward movement of enzymes through cisternae

same

different

• triskelion
• 3 HC and 3 LC
• the arms overlap to a geodesic dome

Clathrin and adaptors uncoat for reuse

uncoating requires ATP

• defect in M6P enzymes in cis golgi
• all enzymes are secreted instead of being delivered to a lysosome

KDEL receptors have what sorting signal?

M6P receptors?

KKXX

DXXLL

KDEL receptors function?

M6P?

• transport cargo from CGN to RER using COP1
• transport lysosomal enzymes to existing lysosome or to form a new one

SNARE hypothesis?

tethering

docking

fusion

tethering - rab G proteins are PMP that bind to specific receptors on membranes; also bind tethering proteins

docking - v snares bind to specific t snares (IMPs) at the target membrane.

Fusion - twisting of snares causing the membranes to fuse

receptor mediated endocytosis (RME)?

cholesterol example

1. LDL binds LDL receptor binds with high affinity
2. sorting signal try-x-x-theta binds to AP2 (adaptor) 
3. clathrin binds AP2

1. clathrin uncoats
2. H+ are pumped in to increase pH
3. LDL receptors lose affinity for LDL
4. LDL receptors bud from sorting compartment and recycle to the PM
5. LDL winds up in lysosome where it is degraded and releases cholesterol

• plus = beta
• minus = alpha

• gamma subunit that is attached at MTOC preferentially binds alpha subunit or minus end.

• MTs fluctuate between slow polymerization and rapid depolym
• allows for rapid changes in MT network
• used in prometaphase to attach to chromosomes

1. dyneins
2. kinesins
3. myosins

1. bind and hydrolyze ATP
2. use ATP to create a conformational change to bind to cytoskeletion
3. change conformation to generate force against the cytoskeleton

• minus end directed
• move organelles
• cilia and flagella
• attach to chroms?

• plus end directed
• move organelles
• move chroms?
• assemble mitotic spindle

• 1 ATP/step
• 1 step = one subunit
• coordinated mvmt of heads 

• must ahve ATP bound in order to polym
• plus end polym more than minus end

1. myosin motor proteins use ATPases to move PGs
2. actin polymerization can push against the cell membrane via actin binding proteins

• most are plus end directed
• bind and hydrolyze ATP to generate force against actin

• dispersion
• detaches from PG during aggregation

• bipolar filaments

1. actin polymerization pushes cell PM
2. attachment of PM to substrate via IMP focal adhesion
3. myosin based contraction to pull tail
4. cell back to normal

• centrosomes duplicate
• chroms condensed
• nuclear envelope degenerates

• high DI, which makes it easy for MTs to bind kinetochores
• opposing motor forces and poly/depolym moves the chromatids toward the equator
• tubulin adds at plus end of short MTs and depolym at plus ends of long MTs

• Chromatids are aligned at equator
• metaphase/anaphase checkpoint makes sure all chromosomes are aligned at equator

• sister chromatids separate and move to opposite poles of the cell
• KMTs shorten at the kinetochore;Dyneins are localized

• spindle elongates
• MT plus directed motors help push spindles to the poles

• chromosomes unwind
• spindle disassembles
• nuclear envelope reassembles to form two nuclei

• a contractile ring of actin and myosin constricts the PM like a purse string

• cohesion proteins
• separase protease
• securin

• Mad1 and Bub1 are not attached to a MT therefore they activate Mad2
• Activated Mad2 will bind Cdc20
• Cdc20 needs to bind Anaphase promoting complex (APC) in order for it to function
• therefore anaphase is delayed

1. Ubiquinating enzyme - marks for destruction
2. adaptor protein

• APC ubiquinates securin (inhibits protease) for destruction
• Separase protease is then fxnal

• catalytic subunit; cyclin dependent kinase; cyclin causes shape change so cyclin-dependent
• regulatory subunit; cyclin protein whose levels fluctuate throughout the cell cycle

• phosphorylate activating AA
• dephosphorylate inhibiting AAs
• phosphorylate inhibiting AAs