| molecular function | 
|      | GO:0046872 |      | metal ion binding |      | Interacting selectively and non-covalently with any metal ion. | 
|      | GO:0005515 |      | protein binding |      | Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules). | 
|      | GO:0008270 |      | zinc ion binding |      | Interacting selectively and non-covalently with zinc (Zn) ions. | 
  | biological process | 
|      | GO:0030036 |      | actin cytoskeleton organization |      | A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of cytoskeletal structures comprising actin filaments and their associated proteins. | 
|      | GO:0030154 |      | cell differentiation |      | The process in which relatively unspecialized cells, e.g. embryonic or regenerative cells, acquire specialized structural and/or functional features that characterize the cells, tissues, or organs of the mature organism or some other relatively stable phase of the organism's life history. Differentiation includes the processes involved in commitment of a cell to a specific fate and its subsequent development to the mature state. | 
|      | GO:0007275 |      | multicellular organism development |      | The biological process whose specific outcome is the progression of a multicellular organism over time from an initial condition (e.g. a zygote or a young adult) to a later condition (e.g. a multicellular animal or an aged adult). | 
|      | GO:0001503 |      | ossification |      | The formation of bone or of a bony substance, or the conversion of fibrous tissue or of cartilage into bone or a bony substance. | 
|      | GO:0045669 |      | positive regulation of osteoblast differentiation |      | Any process that activates or increases the frequency, rate or extent of osteoblast differentiation. | 
|      | GO:0006898 |      | receptor-mediated endocytosis |      | An endocytosis process in which cell surface receptors ensure specificity of transport. A specific receptor on the cell surface binds tightly to the extracellular macromolecule (the ligand) that it recognizes; the plasma-membrane region containing the receptor-ligand complex then undergoes endocytosis, forming a transport vesicle containing the receptor-ligand complex and excluding most other plasma-membrane proteins. Receptor-mediated endocytosis generally occurs via clathrin-coated pits and vesicles. | 
  | cellular component | 
|      | GO:0015629 |      | actin cytoskeleton |      | The part of the cytoskeleton (the internal framework of a cell) composed of actin and associated proteins. Includes actin cytoskeleton-associated complexes. | 
|      | GO:0005737 |      | cytoplasm |      | All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. | 
|      | GO:0005856 |      | cytoskeleton |      | Any of the various filamentous elements that form the internal framework of cells, and typically remain after treatment of the cells with mild detergent to remove membrane constituents and soluble components of the cytoplasm. The term embraces intermediate filaments, microfilaments, microtubules, the microtrabecular lattice, and other structures characterized by a polymeric filamentous nature and long-range order within the cell. The various elements of the cytoskeleton not only serve in the maintenance of cellular shape but also have roles in other cellular functions, including cellular movement, cell division, endocytosis, and movement of organelles. | 
|      | GO:0005925 |      | focal adhesion |      | Small region on the surface of a cell that anchors the cell to the extracellular matrix and that forms a point of termination of actin filaments. | 
|      | GO:0005634 |      | nucleus |      | A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent. | 
|      | GO:0001726 |      | ruffle |      | Projection at the leading edge of a crawling cell; the protrusions are supported by a microfilament meshwork. | 
|      | GO:0001725 |      | stress fiber |      | A contractile actin filament bundle that consists of short actin filaments with alternating polarity, cross-linked by alpha-actinin and possibly other actin bundling proteins, and with myosin present in a periodic distribution along the fiber. |